content: <PAGE>   1
  
  As filed with the Securities and Exchange Commission on June 21, 1996
                                                                  Registration No.
  ===============================================================================
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                               ----------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                               ====================== 
  
                                  CABOT CORPORATION
               (Exact name of Registrant as specified in its charter)
  
                   DELAWARE                                     04-2271897
        (State or other jurisdiction                          (IRS Employer
        of incorporation or organization)                     Identification No.)
  
                                   75 STATE STREET
                             BOSTON, MASSACHUSETTS 02109
             (Address of Principal Executive Office, including zip code)
  
                   NON-EMPLOYEE DIRECTORS' STOCK COMPENSATION PLAN
                              (Full title of the Plan)
  
                             CHARLES D. GERLINGER, ESQ.
                                   75 STATE STREET
                             BOSTON, MASSACHUSETTS 02109
                       (Name and address of agent for service)
  
                                   (617) 342-6170
            (Telephone number, including area code, of agent for service)
  
                               ----------------------
                    APPROXIMATE DATE OF PROPOSED PUBLIC OFFERING:
     As soon as practicable after this Registration Statement becomes effective.
  
                               ----------------------
  <TABLE>
  
                           CALCULATION OF REGISTRATION FEE
  <CAPTION>
  
  - -------------------------------------------------------------------------------
    SECURITIES    AMOUNT TO BE     PROPOSED       PROPOSED
      TO BE        REGISTERED      MAXIMUM        MAXIMUM       AMOUNT OF
    REGISTERED                     OFFERING      AGGREGATE    REGISTRATION
                                  PRICE PER       OFFERING         FEE
                                    SHARE(1)       PRICE(1)
  - -------------------------------------------------------------------------------
  <S>               <C>             <C>         <C>             <C>
  Common Stock,
    par value
      $1.00         400,000         $26.88      $10,752,000     $3,707.59
    (including      shares(2)
    Preferred
      Stock
     Purchase
     Rights)
  - -------------------------------------------------------------------------------
  
  <FN>
  
  (1) Estimated solely for the purpose of determining the registration fee
      pursuant to Rule 457(h) on the basis of the average of the high and low
      prices of Cabot Corporation's Common Stock, par value $1.00, reported on the
      New York Stock Exchange Composite Transactions Index for June 19, 1996.
  
  (2) Plus such indeterminate number of additional shares of Common Stock as
      may be required in the event of a stock dividend, reverse stock split or
      combination of shares, recapitalization or other change in the Company's
      capital stock. Prior to the occurrence of certain events, the Preferred 
      Stock Purchase Rights will not be evidenced separately from the Common 
      Stock.
  
  
  </TABLE>
  
  
  
  <PAGE>   2
  
        Explanatory Note
  
        This registration statement (together with all exhibits hereto (the
  "Registration Statement")), has been prepared in accordance with the
  requirements of the Securities Act of 1933 (the "1933 Act") to register shares
  of common stock of Cabot Corporation, par value $1.00 per share, with attached
  preferred stock purchase rights ("Common Stock"), offered pursuant to the Cabot
  Corporation Non-Employee Directors' Stock Compensation Plan (the "Plan"). The
  documents containing the information specified in Part I of this Form S-8
  Registration Statement will be sent or given to participants as specified by
  Rule 428(b)(1). Such documents and the documents incorporated by reference in
  this Registration Statement pursuant to Item 3 of Part II of this Form S-8,
  taken together, constitute a prospectus that meets the requirements of Section
  10(a) of the 1933 Act.
  
        Under cover of this Registration Statement is a reoffer prospectus
  prepared in accordance with the requirements of Part I of Form S-3 of the 1933 
  Act. Pursuant to General Instruction C of Form S-8 under the 1933 Act, this 
  Registration Statement registers reofferings of up to 400,000 shares of the 
  Common Stock acquired by certain selling stockholders through their 
  participation in the Plan. The Registrant satisfies the requirements for use 
  of Form S-3.
  
  Form S-8 CROSS REFERENCE SHEET SHOWING LOCATION OF INFORMATION REQUIRED BY PART
  I OF FORM S-3 FOR THE REOFFERING OF COMMON STOCK BY SELLING STOCKHOLDERS.
  
  Form S-3 Item Number                            Location/Heading in Prospectus
  - --------------------                            ------------------------------
  
  1. Forepart of Registration Statement and.......Cover Page; Available 
     Outside Front Cover Page of Prospectus       Information
  
  2. Inside Front and Outside Back Cover..........Available Information; 
     Pages of Prospectus                          Incorporation of Certain  
                                                  Information by Reference
  
  3. Summary Information, Risk Factors ...........Cover Page
     and Ratio of Earnings to Fixed Charges
  
  4. Use of Proceeds..............................Use of Proceeds
  
  5. Determination of Offering Price..............Not Applicable
  
  6. Dilution.....................................Not Applicable
  
  7. Selling Security Holders.....................Principal and Selling
                                                  Stockholders
  
  8. Plan of Distribution.........................Plan of Distribution
  
  9. Description of Securities to be Registered...Incorporation of Certain
                                                  Information by Reference
  
  10. Interests of Named Experts and Counsel......Experts
  
  11. Material Changes............................Part II, Item 3 Incorporation of
                                                  Certain Documents by Reference
  
  12. Incorporation of Certain Information .......Incorporation of Certain 
      by Reference                                Information by Reference
  
  13. Disclosure of Commission Position...........Part II, Item 9 Undertakings
      on Indemnification for Securities Act
      Liabilities
  
  
  
  <PAGE>   3
  
  PROSPECTUS
                                  CABOT CORPORATION
                                  400,000 SHARES OF
                                    COMMON STOCK
                                  ($1.00 PAR VALUE)
  
        This Prospectus relates to the offer and sale of 400,000 shares (the
  "Shares") of common stock, par value $1.00 per share, including Preferred Stock
  Purchase Rights relating thereto (the "Common Stock"), of Cabot Corporation, a
  Delaware corporation, ("Cabot" or the "Company") which may be offered hereby
  from time to time by certain non-employee directors or former non-employee
  directors of the Company, participants in the Company's Non-Employee Directors'
  Stock Compensation Plan (the "Plan") and named herein (each a "Selling
  Stockholder"). Certain of the Shares have been acquired by the Selling
  Stockholders from the Company in transactions not involving a public offering
  within the meaning of Section 4(2) of the Securities Act of 1933 (the "1933
  Act") pursuant to the Plan. The Selling Stockholders also may be deemed
  affiliates of the Company (as defined in Rule 405 of the 1933 Act). See
  "Principal and Selling Stockholders." The Company will not receive any of the
  proceeds from the sale of the Shares by the Selling Stockholders.
  
        Alternatively, the Shares may be sold from time to time in one or more
  transactions (which may involve one or more block transactions) on the New York
  Stock Exchange, the Pacific Stock Exchange or the Boston Stock Exchange, or in
  sales occurring in the public market of such Exchanges, in separately negotiated
  transactions, or in a combination of such transactions. Each sale may be made
  either at market prices prevailing at the time of such sale or at negotiated
  prices. Some or all of the Shares may be sold through brokers acting on behalf
  of each Selling Stockholder or to dealers for resale by such dealers. In
  connection with such sales, such brokers and dealers may receive compensation in
  the form of discounts or commissions from each Selling Stockholder and/or the
  purchasers of such Shares for whom they act as broker or agent (which discounts
  or commissions are not anticipated to exceed those customary in the types of
  transactions involved). All expenses of registration incurred in connection with
  this offering are being borne by the Company, but all brokerage commissions and
  other expenses incurred by each Selling Stockholder will be payable by such
  Selling Stockholder. See "Plan of Distribution."
  
        The Selling Stockholders and any dealer participating in the distribution
  of any Shares or any broker executing selling orders on behalf of the Selling
  Stockholders may be deemed to be "underwriters" within the meaning of the Act,
  in which case any profit on the sale of any or all of the Shares by the Selling
  Stockholders and any discounts or commissions received by any such brokers or
  dealers may be deemed to be underwriting discounts and commissions under the
  Act.
  
        The Company's Common Stock is listed on the New York Stock Exchange, the
  Pacific Stock Exchange and the Boston Stock Exchange under the trading symbol
  "CBT". The shares of Common Stock offered hereby are, or are expected to be,
  authorized for listing on such Exchanges.
  
            THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
             SECURITIES AND EXCHANGE COMMISSION OR ANY STATE COMMISSION
                NOR HAS THE SECURITIES AND EXCHANGE COMMISSION OR ANY
                STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY
                 OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION
                       TO THE CONTRARY IS A CRIMINAL OFFENSE.
  
                   THE DATE OF THIS PROSPECTUS IS JUNE 21, 1996
  
  
  
  
  <PAGE>   4
  
                               TABLE OF CONTENTS                             Page
                               -----------------                             ----
  
  
  
  AVAILABLE INFORMATION........................................................2
  
  INCORPORATION OF CERTAIN INFORMATION BY REFERENCE............................2
  
  THE COMPANY..................................................................3
  
  USE OF PROCEEDS..............................................................3
  
  PRINCIPAL AND SELLING STOCKHOLDERS...........................................4
  
  PLAN OF DISTRIBUTION.........................................................5
  
  EXPERTS......................................................................5
  
  INDEMNIFICATION OF DIRECTORS AND OFFICERS....................................5
  
        No person has been authorized to give any information or to make any
  representation in connection with this offering other than those contained in
  this Prospectus. If given or made, such information or representations must not
  be relied upon as having been authorized by the Company. This Prospectus does
  not constitute an offer to sell, or a solicitation of an offer to buy, any
  securities other than the registered securities to which it relates, or an offer
  to or solicitation of any person in any jurisdiction in which such offer or
  solicitation would be unlawful. The delivery of this Prospectus at any time does
  not imply that information herein is correct as of any time subsequent to its
  date.
  
  
  
  
  
  
  
                                       -1-
  
  
  
  
  
  <PAGE>   5
  
        AVAILABLE INFORMATION
  
        Cabot Corporation is subject to the informational requirements of the
  Securities Exchange Act of 1934, as amended (the "Exchange Act"), and, in
  accordance therewith, files reports, proxy materials and other information with
  the Securities and Exchange Commission (the "Commission"). Such reports, proxy
  materials and other information filed by the Company can be inspected and copied
  at the public reference facilities maintained by the Commission at Judiciary
  Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549 and at the regional
  offices of the Commission located at Seven World Trade Center, 13th Floor, New
  York, New York 10048 and Northwestern Atrium Center, 500 West Madison Street,
  Chicago, Illinois 60661. Copies of such material can also be obtained at
  prescribed rates from the Public Reference Section of the Commission at
  Judiciary Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549. The Company is
  listed on the New York Stock Exchange and such reports and other information
  concerning the Company can also be inspected at the offices of the New York
  Stock Exchange, 20 Broad Street, New York, NY 10005. The Company is also listed
  on the Boston Stock Exchange and the Pacific Stock Exchange.
  
        This Prospectus constitutes a part of the Registration Statement and omits
  certain of the information contained in the Registration Statement and reference
  is hereby made to the Registration Statement for further information with
  respect to the Company and the securities offered hereby. Any statements
  contained herein concerning the provisions of any documents are necessarily
  summaries of such documents and not complete, and each statement is qualified in
  its entirety by reference to the copy of the applicable document filed with the
  Commission.
  
        INCORPORATION OF CERTAIN INFORMATION BY REFERENCE
  
        The following documents heretofore filed with the Commission by the
  Company are incorporated by reference in this Prospectus:
  
        (a) The Company's Annual Report on Form 10-K for the fiscal year ended
  September 30, 1995, filed under Section 13 of the Exchange Act.
  
        (b) The Company's Quarterly Report on Form 10-Q for the quarter ended
  December 31, 1995, filed under Section 13 of the Exchange Act.
  
        (c) The Company's Quarterly Report on Form 10-Q for the quarter ended
  March 31, 1996, filed under Section 13 of the Exchange Act.
  
        (d) The description of the Company's Common Stock contained in the
  Company's Registration Statement on Form 10 filed pursuant to Section 12 of the
  Exchange Act and the description of the Company's Preferred Stock Purchase
  Rights contained in the Company's Registration Statement on Form 8-A filed
  pursuant to Section 12 of the Exchange Act.
  
        All reports and other documents subsequently filed by the Company pursuant
  to Sections 13, 14 or 15(d) of the Exchange Act, prior to filing a
  post-effective amendment which indicates that all securities offered hereby have
  been sold or which deregisters all securities remaining unsold, shall be deemed
  incorporated by reference herein and to be part hereof from the date of filing
  of such report and documents. Any statement contained in a report or document 
  incorporated or deemed to be incorporated by reference in this Prospectus shall
  be deemed to be modified or superseded for purposes of this Prospectus to the 
  extent that a statement contained herein or in a subsequently filed document 
  which also is or is deemed to be incorporated by reference in this Prospectus 
  modifies or supersedes such statement. Any such statement so modified or 
  superseded shall not be deemed, except as so modified or superseded, to
  
  
  
                                         -2-
  
  
  
  <PAGE>   6
  
  
  constitute a part of this Prospectus.
  
        The Company undertakes to provide without charge to each person, including
  any beneficial owner, to whom a copy of this Prospectus is delivered, upon the
  written or oral request of such person, a copy of any and all of the information
  described above that has been incorporated herein by reference (other than
  exhibits to such documents unless such exhibits are specifically incorporated by
  reference into such documents). Requests for such information may be directed to
  Thomas W. McNaughton, Jr., Director, Investor Relations, Cabot Corporation, 75
  State Street, Boston, Massachusetts 02109; telephone number (617) 342-6242.
  
        THE COMPANY
  
        Cabot Corporation and its subsidiaries (the "Company") have businesses in
  specialty chemicals and materials and in energy. The Specialty Chemicals and
  Materials Group manufactures carbon black, fumed silica, thermoplastic
  concentrates and specialty compounds, and electronic materials and refractory
  metals. Carbon black is a very fine black powder used as a reinforcing agent in
  tires and industrial rubber products such as extruded profiles, hoses and molded
  goods. Special blacks are used to provide pigmentation, conductivity and
  ultraviolet protection and for other purposes in many specialty applications
  such as inks, plastics, cables and coatings. Fumed silica is an ultra-fine,
  high-purity silica used as a reinforcing, thickening, suspending or anti-caking
  agent in a wide variety of products for the automotive, construction and
  consumer industries, including adhesives, cosmetics, inks, lubricants, paints
  and pharmaceuticals. High-purity polishing compounds, made by the Company from
  fumed metal oxides and a variety of chemistries, are used in the manufacture of
  wafers, chips and other electronic devices by the semiconductor industry. The
  Company produces black and white thermoplastics concentrates and specialty
  compounds for sale to plastic resin producers and the plastics processing
  industry. The major applications for these materials include plastic pipe and
  tubing, plastic packaging and agricultural film, automotive components, cable
  sheathing and special packaging for use in the electronics industry. The Company
  also produces tantalum in various forms including powder, wire, sheet and foil
  for electrolytic capacitors. Both tantalum and niobium and their alloys are
  produced by the Company in wrought form for non-electronic applications such as
  chemical process equipment and the production of superalloys, and for various
  other industrial, defense, aerospace and medical applications. The Company
  maintained an approximately 42.5% ownership interest in Cabot Safety
  Corporation, after restructuring the Company's safety products and specialty
  composites business in July 1995. Cabot Safety Corporation manufactures and
  sells personal safety products, as well as energy absorbing, vibration damping
  and impact absorbing products for industrial noise control and environmental
  enhancement. The Company's principal executive offices are located at 75 State
  Street, Boston, MA 02109. The telephone number, including area code, of the
  Company's principal executive offices is (617) 345-0100.
  
        USE OF PROCEEDS
  
        The Company will not receive any of the proceeds from the sale of the
  Shares by the Selling Stockholders.
  
  
  
  
  
                                         -3-
  
  
  <PAGE>   7
  
  
        PRINCIPAL AND SELLING STOCKHOLDERS
  
        The Selling Stockholders consist of non-employee directors of the Company.
  Any or all of the Shares listed below under the heading "Shares Offered" may be
  offered for sale by the Selling Stockholders pursuant hereto. Set forth below is
  the name of each Selling Stockholder, the number of shares of Common Stock
  beneficially owned by each Selling Stockholder as of the most recent
  practicable date, the number of shares of Common Stock that may be offered and
  sold by each Selling Stockholder hereunder and the number of shares of Common 
  Stock to be owned by each Selling Stockholder if all Shares offered hereby by 
  such Selling Stockholder are sold. There can be no assurances that any Selling
  Stockholder will sell all or any of the shares of Common Stock offered by him 
  or her hereunder.
  
                                                               Shares of Common
                        Shares of Common                         Stock Owned 
                       Stock Owned as of                            After
        Name                                  Shares Offered       Offering 
        ----            --------------        --------------       -------- 
  
  
  
  
  
  
  
  
  
  
        Information regarding the sales of securities by the Selling Stockholders
  under the above headings will be provided herein by post-effective amendment at
  such time or times as one or more of the non-employee directors holding shares
  of Common Stock pursuant to the Company's Non-Employee Directors' Stock
  Compensation Plan (the "Plan") wish to avail themselves of this Prospectus.
  
  
        The Shares which may be offered from time to time pursuant hereto by the
  Selling Stockholders represent shares of Common Stock that were acquired by the
  Selling Stockholders under the Plan. Under the Plan, which became effective
  November 8, 1991, each non-employee director of the Company received initially
  1,600 shares (after giving effect to various stock-splits). On January 15th in
  each year, commencing in 1997, each non-employee director will receive 1,600
  shares of Common Stock (or a prorata number if the non-employee director is not
  standing for re-election) for service as a director previously rendered, and to
  be rendered.
  
  
  
  
  
  
  
  
                                         -4-
  
  
  
  <PAGE>   8
  
  
        PLAN OF DISTRIBUTION
  
        Each Selling Stockholder may from time to time and subject to certain
  conditions effect sales of Shares earned by such Selling Stockholder under the
  Company's Plan. Such sales may be made in one or more transactions on the New
  York Stock Exchange ("NYSE") or the Pacific Stock Exchange or the Boston Stock
  Exchange or other securities exchanges or in the over-the-counter market or
  otherwise, at prices and at terms prevailing or at prices related to the then
  current market price, or in negotiated transactions, by gift or otherwise. If
  all or a portion of such shares are sold in transactions on the NYSE or the
  Pacific Stock Exchange or the Boston Stock Exchange, they may be sold by means
  of: (a) a block trade in which the broker or dealer so engaged will attempt to
  sell the shares as agent but may position and resell a portion of the block as
  principal to facilitate the transactions; (b) purchases by a broker as principal
  and resale by such broker for its account pursuant to this Prospectus; (c) an
  Exchange distribution in accordance with the rules of such Exchange; (d)
  ordinary brokerage transactions and transactions in which the broker solicits
  purchasers; or (e) a combination of the foregoing methods. In effecting sales,
  brokers or dealers engaged by a Selling Stockholder may arrange for other
  brokers or dealers to participate. The brokers or dealers engaged by a Selling
  Stockholder may receive commissions or discounts from such Selling Stockholders
  in amounts to be negotiated prior to the sale. Such brokers or dealers and other
  participating brokers or dealers may be deemed to be "underwriters" within the
  meaning of the 1933 Act in connection with such sales.
  
        EXPERTS
  
        The consolidated balance sheets as of September 30, 1995 and 1994 and the
  consolidated statements of operations and cash flows for each of the three years
  in the period ended September 30, 1995, incorporated by reference in this
  Prospectus, have been incorporated by reference herein in reliance on the report
  of Coopers & Lybrand L.L.P., independent accountants, given on the authority of
  that firm as experts in accounting and auditing.
  
        The validity of the shares of Common Stock offered hereby is being passed
  upon for the Company by Robert Rothberg, Esq., Cabot Corporation, 75 State
  Street, Boston, Massachusetts 02109. Mr. Rothberg is a Vice President and the
  General Counsel of the Company. At the time of rendering his opinion as to the
  legality of the Common Stock being registered hereunder, Mr. Rothberg had a
  substantial interest in the Company, as defined by the rules of the Securities
  and Exchange Commission, in that Mr. Rothberg owned 83,294 shares of the
  Company's Common Stock, with a fair market value of in excess of $50,000, and
  had the right to purchase an additional 20,000 shares pursuant to the Company's
  1996 Equity Incentive Plan.
  
        INDEMNIFICATION OF DIRECTORS AND OFFICERS
  
        Article Eighth (j) of the Company's Certificate of Incorporation and
  Section 14 of the Company's by-laws provide that the Company shall indemnify any
  person who was a party, is a party or is threatened to be made a party to any
  threatened, pending or completed action, suit, or proceeding by reason of the
  fact that he is or was a director, officer, employee or agent of the Company or
  is or was serving at the request of the Company as a director, officer, employee
  or agent of another company or enterprise including service as a fiduciary of an
  employee benefit plan against expenses (including attorneys' fees), judgments,
  fines, penalties and amounts paid in settlement incurred in connection with such
  action, suit or proceeding to the extent permitted from time to time under the
  Delaware General Corporation Law. Such indemnification shall be made as
  authorized in a specific case upon a determination by the Board of Directors or
  the stockholders of the Company. The rights of indemnification are not exclusive
  of any other rights to which those seeking
  
  
  
                                         -5-
  
  
  <PAGE>   9
  
  
  indemnification may be entitled and shall continue as to a person who ceases to
  be a director, officer, employee or agent. In addition, under Article Eighth (i)
  no director of the Company shall be liable to the Company or its stockholders
  for monetary damages for any breach of fiduciary duty, except to the extent that
  Delaware General Corporation Law prohibits the elimination or limitation of
  liability of directors for breach of fiduciary duty.
  
        Section 145 of the Delaware General Corporation Law authorizes the
  indemnification of directors, officers, employees and agents against liability
  incurred by reason of being a director, officer, employee or agent, and against
  expenses (including attorneys' fees) in connection with defending any action
  seeking to establish liability, in the case of third-party claims, if such
  person acted in good faith and in a manner he or she reasonably believed to be
  in or not opposed to the best interests of the corporation, unless a court
  otherwise determines. Indemnification is also authorized with respect to any
  criminal action or proceeding where such person had no reasonable cause to
  believe his or her conduct was unlawful.
  
        The Company's current directors' and officers' insurance policies cover
  directors and officers of the Company and its subsidiaries.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
                                         -6-
  
  
  
  
  <PAGE>   10
  
  
  PART II  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  Item 3. Incorporation of Documents by Reference
  
        The following documents filed with the Commission are incorporated herein
  by reference:
  
        (a) The Company's Annual Report on Form 10-K, for the fiscal year ended
  September 30, 1995, filed under Section 13 of the Exchange Act.
  
        (b) The Company's Quarterly Report on Form 10-Q for the quarter ended
  December 31, 1995, filed under Section 13 of the Exchange Act.
  
        (c) The Company's Quarterly Report on Form 10-Q for the quarter ended
  March 31, 1996, filed under Section 13 of the Exchange Act.
  
        (d) The description of the Company's Common Stock contained in the
  Company's Registration Statement on Form 10 filed pursuant to Section 12 of the
  Exchange Act and the description of the Company's Preferred Stock Purchase
  Rights contained in the Company's Registration Statement on Form 8-A filed
  pursuant to Section 12 of the Exchange Act.
  
        All reports and other documents subsequently filed by the Company pursuant
  to Sections 13, 14 or 15(d) of the Exchange Act, prior to filing a
  post-effective amendment which indicates that all securities offered hereby have
  been sold or which deregisters all securities remaining unsold, shall be deemed
  incorporated by reference herein and to be part hereof from the date of the
  filing of such report and documents.
  
  Item 4. Description of Securities
  
        The Company's Common Stock is registered under Section 12 of the Exchange
  Act and the Company's Preferred Stock Purchase Rights is registered under
  Section 12 of the Exchange Act. See Item 3(d) regarding the description of the
  Company's Common Stock and the Company's Preferred Stock Purchase Rights.
  
  Item 5. Interests of Named Experts and Counsel
  
        The validity of the shares of Common Stock offered hereby is being passed
  upon for the Company by Robert Rothberg, Esq. At the time of rendering his
  opinion as to the legality of the Common Stock being registered hereunder, Mr.
  Rothberg had a substantial interest in the Company, as defined by the rules of
  the Securities and Exchange Commission, in that the fair market value of the
  83,294 shares of Common Stock beneficially owned by him exceeds $50,000, and he
  had the right to purchase an additional 20,000 shares pursuant to the Company's
  1996 Equity Incentive Plan. Also, at such time Mr. Rothberg was connected with
  the Company in that he was a Vice President and the General Counsel of the
  Company.
  
  Item 6. Indemnification of Directors and Officers
  
        Article Eighth (j) of the Company's Certificate of Incorporation and
  Section 14 of the Company's by-laws provide that the Company shall indemnify any
  person who was a party, is a party or is threatened to be made a party to any
  threatened, pending or completed action, suit, or proceeding by reason of the
  fact that he or she is or was a director, officer, employee or agent of the
  Company or is or was serving at the request of the Company as a director,
  officer, employee or agent of another company or enterprise including service as
  a fiduciary of an employee benefit plan against expenses (including attorneys'
  fees), judgments, fines, penalties and amounts paid in settlement incurred in
  connection with such action, suit or proceeding to the extent permitted from
  time to time under the Delaware General Corporation Law. Such indemnification
  shall be
           
  
  
                                      Page II-1
  
  
  <PAGE>   11
  
  
  made as authorized in a specific case upon a determination by the Board of
  Directors or the stockholders of the Company. The rights of indemnification are
  not exclusive of any other rights to which those seeking indemnification may be
  entitled and shall continue as to a person who ceases to be a director, officer,
  employee or agent. In addition, under Article Eighth (i) no director of the
  Company shall be liable to the Company or its stockholders for monetary damages
  for any breach of fiduciary duty, except to the extent that Delaware General
  Corporation Law prohibits the elimination or limitation of liability of
  directors for breach of fiduciary duty.
  
        Section 145 of the Delaware General Corporation Law authorizes the
  indemnification of directors, officers, employees and agents against liability
  incurred by reason of being a director, officer, employee or agent, and against
  expenses (including attorneys' fees) in connection with defending any action
  seeking to establish liability, in the case of third-party claims, if such
  person acted in good faith and in a manner he or she reasonably believed to be
  in or not opposed to the best interests of the corporation, unless a court
  otherwise determines. Indemnification is also authorized with respect to any
  criminal action or proceeding where such person had no reasonable cause to
  believe his or her conduct was unlawful.
  
        The Company's current directors' and officers' insurance policies cover
  directors and officers of the Company and its subsidiaries.
  
  Item 7. Exemption from Registration Claimed
  
        Certain of the shares of Common Stock to be resold by the Selling
  Stockholders named in the Prospectus prepared in accordance with Part I of Form
  S-3 were issued by the Registrant to the Selling Stockholders pursuant to an
  exemption from registration under the Act by virtue of Section 4(2) thereof. The
  shares were issued to the Selling Stockholders pursuant to the Registrant's
  Non-Employee Directors' Stock Compensation Plan, a written plan in connection
  with the Selling Stockholders' service as outside directors for the Company. The
  Selling Stockholders had access, by virtue of their positions on the Company's
  Board of Directors, to sufficient information to make an informed investment
  decision.
  
  Item 8. Exhibits
  
        Exhibit
        Number
        ------
           5     Opinion of Robert Rothberg.
          23.1   Consent of Robert Rothberg is contained in his opinion
                 filed as Exhibit 5 to this Registration Statement.
          23.2   Consent of Coopers & Lybrand L.L.P.
          24     Power of Attorney.
          99     Non-Employee Directors' Stock Compensation Plan.
  
  Item 9. Undertakings
  
        A. Subsequent Exchange Act Documents.
  
        The undersigned registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Securities Exchange Act of 1934 (and, where applicable, each filing of an
  employee benefit plan's annual report pursuant to Section 15(d) of the
  Securities Exchange Act of 1934) that is incorporated by reference in the
  Registration Statement shall be deemed to be a new registration statement
  relating to the securities offered therein, and the offering of such securities
  at that time shall be deemed to be the initial bona fide offering thereof.
  
  
  
                                      Page II-2
  
  
  <PAGE>   12
  
  
  
        B. To Transmit Certain Material.
  
        The undersigned registrant hereby undertakes to deliver or cause to be
  delivered with the prospectus to each person to whom the prospectus is sent or
  given, a copy of the registrant's latest annual report to stockholders furnished
  pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the
  Securities Exchange Act of 1934. Where interim financial information required to
  be presented by Article 3 of Regulation S-X is not set forth in the prospectus,
  the undersigned also undertakes to deliver, or cause to be delivered to each
  person to whom the prospectus is sent or given, the latest quarterly report that
  is specifically incorporated by reference in the prospectus to provide such
  interim financial information.
  
        C. Undertaking to Update Annually.
  
        The undersigned registrant hereby undertakes: (1) to file during any
  period in which offers or sales are made, a post-effective amendment to the
  registration statement: (i) to include any prospectus required by Section
  10(a)(3) of the Securities Act of 1933; (ii) to reflect in the prospectus any
  facts or events arising after the effective date of the registration statement
  (or the most recent post-effective amendment thereof) which, individually or in
  the aggregate, represent a fundamental change in the information set forth in
  the registration statement; and (iii) to include any material information with
  respect to the plan of distribution not previously disclosed in the registration
  statement or any material change in such information in the registration
  statement; (2) that, for the purpose of determining any liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein, and the
  offering of such securities shall be deemed to be the initial bona fide offering
  thereof; and (3) to remove from registration by means of a post-effective
  amendment any of the securities being registered which remain unsold at the
  termination of the offering. Provided, however, that if the information required
  to be included in a post-effective amendment by clauses (1)(i) and (1)(ii) of
  this paragraph is contained in periodic reports filed with or furnished to the
  Commission by the registrant pursuant to Section 13 or Section 15(d) of the
  Securities Exchange Act of 1934 that are incorporated by reference in the
  registration statement, the registrant need not file a post-effective amendment
  to provide such information.
  
        D. Indemnification.
  
        Insofar as indemnification for liabilities arising under the Securities
  Act of 1933 may be permitted to directors, officers and controlling persons of
  the registrant pursuant to the foregoing provisions, or otherwise, the
  registrant has been advised that in the opinion of the Securities and Exchange
  Commission such indemnification is against public policy as expressed in the Act
  and is, therefore, unenforceable. In the event that a claim for indemnification
  against such liabilities (other than the payment by the registrant of expenses
  incurred or paid by a director, officer or controlling person of the registrant
  in the successful defense of any action, suit or proceeding) is asserted by such
  director, officer or controlling person in connection with the securities being
  registered, the registrant will, unless in the opinion of its counsel the matter
  has been settled by controlling precedent, submit to a court of appropriate
  jurisdiction the question whether such indemnification by it is against public
  policy as expressed in the Act and will be governed by the final adjudication of
  such issue.
  
  
  
                                      Page II-3
  
  
  
  <PAGE>   13
  
                                    SIGNATURES
  
        Pursuant to the requirements of the Securities Act of 1933, the Registrant
  certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form S-8 and has duly caused this Registration
  Statement to be signed on its behalf by the undersigned, thereunto duly
  authorized, in the City of Boston, and the Commonwealth of Massachusetts, 
  June XX, 1996.
  
  
  
                                            CABOT CORPORATION
  
                                            By /s/ Kenyon C. Gilson
                                               ------------------------------
                                               Kenyon C. Gilson                 
                                               Executive Vice President
                                               and Chief Financial Officer
  
        PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, THIS
  REGISTRATION STATEMENT HAS BEEN SIGNED BELOW BY THE FOLLOWING PERSONS IN THE
  CAPACITIES AND ON THE DATE INDICATED.
  
        SIGNATURE                                 TITLE                 DATE
        ---------                                 -----                 ----
  
  PRINCIPAL EXECUTIVE OFFICER
  
  /s/       *                            Chairman of the Board      June 21, 1996
  - ----------------------------------     of Directors and Chief
        (Samuel W. Bodman)               Executive Officer     
  
                                      
  PRINCIPAL FINANCIAL OFFICER
  
  /s/ Kenyon C. Gilson                   Executive Vice President   June 21, 1996
  - ----------------------------------     and Chief Financial 
        (Kenyon C. Gilson)               Officer
                             
  
  
  PRINCIPAL ACCOUNTING OFFICER           
  
  /s/       *                            Vice President             June 21, 1996
  - ----------------------------------     and Controller
        (Paul J. Gormisky)
  
  
  MAJORITY OF THE BOARD OF DIRECTORS
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Kennett F. Burnes)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Jane C. Bradley)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (John G.L. Cabot)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Arthur L. Goldstein)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Robert P. Henderson)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Arnold S. Hiatt)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (John H. McArthur)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (John F. O'Brien)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (David V. Ragone)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
       (Charles P. Siess, Jr.)
  
  
  
  
                                    Page II-4
  
  
  <PAGE>   14
  
  
        SIGNATURE                                 TITLE                 DATE
        ---------                                 -----                 ----
  
  
                *                        Director                   June 21, 1996
  - ----------------------------------
        (Morris Tanenbaum)
  
                *                        Director                   June 21, 1996
  - ----------------------------------
        (Lydia W. Thomas)
  
  
  
  *By /s/ CHARLES D. GERLINGER                                      June 21, 1996
      ------------------------------
          Charles D. Gerlinger
          As Attorney-in-Fact**
  
  
  - ---------------------
  ** By authority of Power of Attorney filed as Exhibit 24 to this Registration
  Statement
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
                                      Page II-5
  
  
  
  
  
  <PAGE>   15
  
                                    EXHIBIT INDEX
  
  
  
  
  
  Exhibit
  Number                                                                   Page
  - ------                                                                   ----
  
  
  5           Opinion of Robert Rothberg, Vice President and
              General Counsel.
  
  23.1        Consent of Robert Rothberg is contained in the
              Opinion filed as Exhibit 5 to this Registration Statement.
  
  23.2        Consent of Coopers & Lybrand L.L.P.
  
  24          Power of Attorney.
  
  99          Non-Employee Directors' Stock Compensation Plan.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
                                      Page II-6
metadata_documents: [{"type": "S-8", "sequence": "1", "description": "CABOT CORPORATION", "secsgml_size_bytes": 42689}]
metadata_filer: {"company-data": {"conformed-name": "CABOT CORP", "cik": "0000016040", "assigned-sic": "2890", "irs-number": "042271897", "state-of-incorporation": "DE", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-06629", "film-number": "96584271"}, "business-address": {"street1": "75 STATE ST", "city": "BOSTON", "state": "MA", "zip": "02109-1806", "phone": "6173450100"}, "mail-address": {"street1": "75 STATE ST", "city": "BOSTON", "state": "MA", "zip": "82109"}, "former-company": {"former-conformed-name": "CABOT GODFREY L INC", "date-changed": "19680418"}}
text: 1
  
  As filed with the Securities and Exchange Commission on June 21, 1996
                                                                  Registration No.
  ===============================================================================
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                               ----------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                               ====================== 
  
                                  CABOT CORPORATION
               (Exact name of Registrant as specified in its charter)
  
                   DELAWARE                                     04-2271897
        (State or other jurisdiction                          (IRS Employer
        of incorporation or organization)                     Identification No.)
  
                                   75 STATE STREET
                             BOSTON, MASSACHUSETTS 02109
             (Address of Principal Executive Office, including zip code)
  
                   NON-EMPLOYEE DIRECTORS' STOCK COMPENSATION PLAN
                              (Full title of the Plan)
  
                             CHARLES D. GERLINGER, ESQ.
                                   75 STATE STREET
                             BOSTON, MASSACHUSETTS 02109
                       (Name and address of agent for service)
  
                                   (617) 342-6170
            (Telephone number, including area code, of agent for service)
  
                               ----------------------
                    APPROXIMATE DATE OF PROPOSED PUBLIC OFFERING:
     As soon as practicable after this Registration Statement becomes effective.
  
                               ----------------------
  
                           CALCULATION OF REGISTRATION FEE
  - -------------------------------------------------------------------------------
    SECURITIES    AMOUNT TO BE     PROPOSED       PROPOSED
      TO BE        REGISTERED      MAXIMUM        MAXIMUM       AMOUNT OF
    REGISTERED                     OFFERING      AGGREGATE    REGISTRATION
                                  PRICE PER       OFFERING         FEE
                                    SHARE(1)       PRICE(1)
  - -------------------------------------------------------------------------------
  Common Stock,
    par value
      $1.00         400,000         $26.88      $10,752,000     $3,707.59
    (including      shares(2)
    Preferred
      Stock
     Purchase
     Rights)
  - -------------------------------------------------------------------------------
  (1) Estimated solely for the purpose of determining the registration fee
      pursuant to Rule 457(h) on the basis of the average of the high and low
      prices of Cabot Corporation's Common Stock, par value $1.00, reported on the
      New York Stock Exchange Composite Transactions Index for June 19, 1996.
  
  (2) Plus such indeterminate number of additional shares of Common Stock as
      may be required in the event of a stock dividend, reverse stock split or
      combination of shares, recapitalization or other change in the Company's
      capital stock. Prior to the occurrence of certain events, the Preferred 
      Stock Purchase Rights will not be evidenced separately from the Common 
      Stock.
  2
  
        Explanatory Note
  
        This registration statement (together with all exhibits hereto (the
  "Registration Statement")), has been prepared in accordance with the
  requirements of the Securities Act of 1933 (the "1933 Act") to register shares
  of common stock of Cabot Corporation, par value $1.00 per share, with attached
  preferred stock purchase rights ("Common Stock"), offered pursuant to the Cabot
  Corporation Non-Employee Directors' Stock Compensation Plan (the "Plan"). The
  documents containing the information specified in Part I of this Form S-8
  Registration Statement will be sent or given to participants as specified by
  Rule 428(b)(1). Such documents and the documents incorporated by reference in
  this Registration Statement pursuant to Item 3 of Part II of this Form S-8,
  taken together, constitute a prospectus that meets the requirements of Section
  10(a) of the 1933 Act.
  
        Under cover of this Registration Statement is a reoffer prospectus
  prepared in accordance with the requirements of Part I of Form S-3 of the 1933 
  Act. Pursuant to General Instruction C of Form S-8 under the 1933 Act, this 
  Registration Statement registers reofferings of up to 400,000 shares of the 
  Common Stock acquired by certain selling stockholders through their 
  participation in the Plan. The Registrant satisfies the requirements for use 
  of Form S-3.
  
  Form S-8 CROSS REFERENCE SHEET SHOWING LOCATION OF INFORMATION REQUIRED BY PART
  I OF FORM S-3 FOR THE REOFFERING OF COMMON STOCK BY SELLING STOCKHOLDERS.
  
  Form S-3 Item Number                            Location/Heading in Prospectus
  - --------------------                            ------------------------------
  
  1. Forepart of Registration Statement and.......Cover Page; Available 
     Outside Front Cover Page of Prospectus       Information
  
  2. Inside Front and Outside Back Cover..........Available Information; 
     Pages of Prospectus                          Incorporation of Certain  
                                                  Information by Reference
  
  3. Summary Information, Risk Factors ...........Cover Page
     and Ratio of Earnings to Fixed Charges
  
  4. Use of Proceeds..............................Use of Proceeds
  
  5. Determination of Offering Price..............Not Applicable
  
  6. Dilution.....................................Not Applicable
  
  7. Selling Security Holders.....................Principal and Selling
                                                  Stockholders
  
  8. Plan of Distribution.........................Plan of Distribution
  
  9. Description of Securities to be Registered...Incorporation of Certain
                                                  Information by Reference
  
  10. Interests of Named Experts and Counsel......Experts
  
  11. Material Changes............................Part II, Item 3 Incorporation of
                                                  Certain Documents by Reference
  
  12. Incorporation of Certain Information .......Incorporation of Certain 
      by Reference                                Information by Reference
  
  13. Disclosure of Commission Position...........Part II, Item 9 Undertakings
      on Indemnification for Securities Act
      Liabilities
  3
  
  PROSPECTUS
                                  CABOT CORPORATION
                                  400,000 SHARES OF
                                    COMMON STOCK
                                  ($1.00 PAR VALUE)
  
        This Prospectus relates to the offer and sale of 400,000 shares (the
  "Shares") of common stock, par value $1.00 per share, including Preferred Stock
  Purchase Rights relating thereto (the "Common Stock"), of Cabot Corporation, a
  Delaware corporation, ("Cabot" or the "Company") which may be offered hereby
  from time to time by certain non-employee directors or former non-employee
  directors of the Company, participants in the Company's Non-Employee Directors'
  Stock Compensation Plan (the "Plan") and named herein (each a "Selling
  Stockholder"). Certain of the Shares have been acquired by the Selling
  Stockholders from the Company in transactions not involving a public offering
  within the meaning of Section 4(2) of the Securities Act of 1933 (the "1933
  Act") pursuant to the Plan. The Selling Stockholders also may be deemed
  affiliates of the Company (as defined in Rule 405 of the 1933 Act). See
  "Principal and Selling Stockholders." The Company will not receive any of the
  proceeds from the sale of the Shares by the Selling Stockholders.
  
        Alternatively, the Shares may be sold from time to time in one or more
  transactions (which may involve one or more block transactions) on the New York
  Stock Exchange, the Pacific Stock Exchange or the Boston Stock Exchange, or in
  sales occurring in the public market of such Exchanges, in separately negotiated
  transactions, or in a combination of such transactions. Each sale may be made
  either at market prices prevailing at the time of such sale or at negotiated
  prices. Some or all of the Shares may be sold through brokers acting on behalf
  of each Selling Stockholder or to dealers for resale by such dealers. In
  connection with such sales, such brokers and dealers may receive compensation in
  the form of discounts or commissions from each Selling Stockholder and/or the
  purchasers of such Shares for whom they act as broker or agent (which discounts
  or commissions are not anticipated to exceed those customary in the types of
  transactions involved). All expenses of registration incurred in connection with
  this offering are being borne by the Company, but all brokerage commissions and
  other expenses incurred by each Selling Stockholder will be payable by such
  Selling Stockholder. See "Plan of Distribution."
  
        The Selling Stockholders and any dealer participating in the distribution
  of any Shares or any broker executing selling orders on behalf of the Selling
  Stockholders may be deemed to be "underwriters" within the meaning of the Act,
  in which case any profit on the sale of any or all of the Shares by the Selling
  Stockholders and any discounts or commissions received by any such brokers or
  dealers may be deemed to be underwriting discounts and commissions under the
  Act.
  
        The Company's Common Stock is listed on the New York Stock Exchange, the
  Pacific Stock Exchange and the Boston Stock Exchange under the trading symbol
  "CBT". The shares of Common Stock offered hereby are, or are expected to be,
  authorized for listing on such Exchanges.
  
            THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
             SECURITIES AND EXCHANGE COMMISSION OR ANY STATE COMMISSION
                NOR HAS THE SECURITIES AND EXCHANGE COMMISSION OR ANY
                STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY
                 OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION
                       TO THE CONTRARY IS A CRIMINAL OFFENSE.
  
                   THE DATE OF THIS PROSPECTUS IS JUNE 21, 1996
  4
  
                               TABLE OF CONTENTS                             Page
                               -----------------                             ----
  
  AVAILABLE INFORMATION........................................................2
  
  INCORPORATION OF CERTAIN INFORMATION BY REFERENCE............................2
  
  THE COMPANY..................................................................3
  
  USE OF PROCEEDS..............................................................3
  
  PRINCIPAL AND SELLING STOCKHOLDERS...........................................4
  
  PLAN OF DISTRIBUTION.........................................................5
  
  EXPERTS......................................................................5
  
  INDEMNIFICATION OF DIRECTORS AND OFFICERS....................................5
  
        No person has been authorized to give any information or to make any
  representation in connection with this offering other than those contained in
  this Prospectus. If given or made, such information or representations must not
  be relied upon as having been authorized by the Company. This Prospectus does
  not constitute an offer to sell, or a solicitation of an offer to buy, any
  securities other than the registered securities to which it relates, or an offer
  to or solicitation of any person in any jurisdiction in which such offer or
  solicitation would be unlawful. The delivery of this Prospectus at any time does
  not imply that information herein is correct as of any time subsequent to its
  date.
  
                                       -1-
  5
  
        AVAILABLE INFORMATION
  
        Cabot Corporation is subject to the informational requirements of the
  Securities Exchange Act of 1934, as amended (the "Exchange Act"), and, in
  accordance therewith, files reports, proxy materials and other information with
  the Securities and Exchange Commission (the "Commission"). Such reports, proxy
  materials and other information filed by the Company can be inspected and copied
  at the public reference facilities maintained by the Commission at Judiciary
  Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549 and at the regional
  offices of the Commission located at Seven World Trade Center, 13th Floor, New
  York, New York 10048 and Northwestern Atrium Center, 500 West Madison Street,
  Chicago, Illinois 60661. Copies of such material can also be obtained at
  prescribed rates from the Public Reference Section of the Commission at
  Judiciary Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549. The Company is
  listed on the New York Stock Exchange and such reports and other information
  concerning the Company can also be inspected at the offices of the New York
  Stock Exchange, 20 Broad Street, New York, NY 10005. The Company is also listed
  on the Boston Stock Exchange and the Pacific Stock Exchange.
  
        This Prospectus constitutes a part of the Registration Statement and omits
  certain of the information contained in the Registration Statement and reference
  is hereby made to the Registration Statement for further information with
  respect to the Company and the securities offered hereby. Any statements
  contained herein concerning the provisions of any documents are necessarily
  summaries of such documents and not complete, and each statement is qualified in
  its entirety by reference to the copy of the applicable document filed with the
  Commission.
  
        INCORPORATION OF CERTAIN INFORMATION BY REFERENCE
  
        The following documents heretofore filed with the Commission by the
  Company are incorporated by reference in this Prospectus:
  
        (a) The Company's Annual Report on Form 10-K for the fiscal year ended
  September 30, 1995, filed under Section 13 of the Exchange Act.
  
        (b) The Company's Quarterly Report on Form 10-Q for the quarter ended
  December 31, 1995, filed under Section 13 of the Exchange Act.
  
        (c) The Company's Quarterly Report on Form 10-Q for the quarter ended
  March 31, 1996, filed under Section 13 of the Exchange Act.
  
        (d) The description of the Company's Common Stock contained in the
  Company's Registration Statement on Form 10 filed pursuant to Section 12 of the
  Exchange Act and the description of the Company's Preferred Stock Purchase
  Rights contained in the Company's Registration Statement on Form 8-A filed
  pursuant to Section 12 of the Exchange Act.
  
        All reports and other documents subsequently filed by the Company pursuant
  to Sections 13, 14 or 15(d) of the Exchange Act, prior to filing a
  post-effective amendment which indicates that all securities offered hereby have
  been sold or which deregisters all securities remaining unsold, shall be deemed
  incorporated by reference herein and to be part hereof from the date of filing
  of such report and documents. Any statement contained in a report or document 
  incorporated or deemed to be incorporated by reference in this Prospectus shall
  be deemed to be modified or superseded for purposes of this Prospectus to the 
  extent that a statement contained herein or in a subsequently filed document 
  which also is or is deemed to be incorporated by reference in this Prospectus 
  modifies or supersedes such statement. Any such statement so modified or 
  superseded shall not be deemed, except as so modified or superseded, to
  
                                         -2-
  6
  
  constitute a part of this Prospectus.
  
        The Company undertakes to provide without charge to each person, including
  any beneficial owner, to whom a copy of this Prospectus is delivered, upon the
  written or oral request of such person, a copy of any and all of the information
  described above that has been incorporated herein by reference (other than
  exhibits to such documents unless such exhibits are specifically incorporated by
  reference into such documents). Requests for such information may be directed to
  Thomas W. McNaughton, Jr., Director, Investor Relations, Cabot Corporation, 75
  State Street, Boston, Massachusetts 02109; telephone number (617) 342-6242.
  
        THE COMPANY
  
        Cabot Corporation and its subsidiaries (the "Company") have businesses in
  specialty chemicals and materials and in energy. The Specialty Chemicals and
  Materials Group manufactures carbon black, fumed silica, thermoplastic
  concentrates and specialty compounds, and electronic materials and refractory
  metals. Carbon black is a very fine black powder used as a reinforcing agent in
  tires and industrial rubber products such as extruded profiles, hoses and molded
  goods. Special blacks are used to provide pigmentation, conductivity and
  ultraviolet protection and for other purposes in many specialty applications
  such as inks, plastics, cables and coatings. Fumed silica is an ultra-fine,
  high-purity silica used as a reinforcing, thickening, suspending or anti-caking
  agent in a wide variety of products for the automotive, construction and
  consumer industries, including adhesives, cosmetics, inks, lubricants, paints
  and pharmaceuticals. High-purity polishing compounds, made by the Company from
  fumed metal oxides and a variety of chemistries, are used in the manufacture of
  wafers, chips and other electronic devices by the semiconductor industry. The
  Company produces black and white thermoplastics concentrates and specialty
  compounds for sale to plastic resin producers and the plastics processing
  industry. The major applications for these materials include plastic pipe and
  tubing, plastic packaging and agricultural film, automotive components, cable
  sheathing and special packaging for use in the electronics industry. The Company
  also produces tantalum in various forms including powder, wire, sheet and foil
  for electrolytic capacitors. Both tantalum and niobium and their alloys are
  produced by the Company in wrought form for non-electronic applications such as
  chemical process equipment and the production of superalloys, and for various
  other industrial, defense, aerospace and medical applications. The Company
  maintained an approximately 42.5% ownership interest in Cabot Safety
  Corporation, after restructuring the Company's safety products and specialty
  composites business in July 1995. Cabot Safety Corporation manufactures and
  sells personal safety products, as well as energy absorbing, vibration damping
  and impact absorbing products for industrial noise control and environmental
  enhancement. The Company's principal executive offices are located at 75 State
  Street, Boston, MA 02109. The telephone number, including area code, of the
  Company's principal executive offices is (617) 345-0100.
  
        USE OF PROCEEDS
  
        The Company will not receive any of the proceeds from the sale of the
  Shares by the Selling Stockholders.
  
                                         -3-
  7
  
        PRINCIPAL AND SELLING STOCKHOLDERS
  
        The Selling Stockholders consist of non-employee directors of the Company.
  Any or all of the Shares listed below under the heading "Shares Offered" may be
  offered for sale by the Selling Stockholders pursuant hereto. Set forth below is
  the name of each Selling Stockholder, the number of shares of Common Stock
  beneficially owned by each Selling Stockholder as of the most recent
  practicable date, the number of shares of Common Stock that may be offered and
  sold by each Selling Stockholder hereunder and the number of shares of Common 
  Stock to be owned by each Selling Stockholder if all Shares offered hereby by 
  such Selling Stockholder are sold. There can be no assurances that any Selling
  Stockholder will sell all or any of the shares of Common Stock offered by him 
  or her hereunder.
  
                                                               Shares of Common
                        Shares of Common                         Stock Owned 
                       Stock Owned as of                            After
        Name                                  Shares Offered       Offering 
        ----            --------------        --------------       -------- 
  
        Information regarding the sales of securities by the Selling Stockholders
  under the above headings will be provided herein by post-effective amendment at
  such time or times as one or more of the non-employee directors holding shares
  of Common Stock pursuant to the Company's Non-Employee Directors' Stock
  Compensation Plan (the "Plan") wish to avail themselves of this Prospectus.
  
        The Shares which may be offered from time to time pursuant hereto by the
  Selling Stockholders represent shares of Common Stock that were acquired by the
  Selling Stockholders under the Plan. Under the Plan, which became effective
  November 8, 1991, each non-employee director of the Company received initially
  1,600 shares (after giving effect to various stock-splits). On January 15th in
  each year, commencing in 1997, each non-employee director will receive 1,600
  shares of Common Stock (or a prorata number if the non-employee director is not
  standing for re-election) for service as a director previously rendered, and to
  be rendered.
  
                                         -4-
  8
  
        PLAN OF DISTRIBUTION
  
        Each Selling Stockholder may from time to time and subject to certain
  conditions effect sales of Shares earned by such Selling Stockholder under the
  Company's Plan. Such sales may be made in one or more transactions on the New
  York Stock Exchange ("NYSE") or the Pacific Stock Exchange or the Boston Stock
  Exchange or other securities exchanges or in the over-the-counter market or
  otherwise, at prices and at terms prevailing or at prices related to the then
  current market price, or in negotiated transactions, by gift or otherwise. If
  all or a portion of such shares are sold in transactions on the NYSE or the
  Pacific Stock Exchange or the Boston Stock Exchange, they may be sold by means
  of: (a) a block trade in which the broker or dealer so engaged will attempt to
  sell the shares as agent but may position and resell a portion of the block as
  principal to facilitate the transactions; (b) purchases by a broker as principal
  and resale by such broker for its account pursuant to this Prospectus; (c) an
  Exchange distribution in accordance with the rules of such Exchange; (d)
  ordinary brokerage transactions and transactions in which the broker solicits
  purchasers; or (e) a combination of the foregoing methods. In effecting sales,
  brokers or dealers engaged by a Selling Stockholder may arrange for other
  brokers or dealers to participate. The brokers or dealers engaged by a Selling
  Stockholder may receive commissions or discounts from such Selling Stockholders
  in amounts to be negotiated prior to the sale. Such brokers or dealers and other
  participating brokers or dealers may be deemed to be "underwriters" within the
  meaning of the 1933 Act in connection with such sales.
  
        EXPERTS
  
        The consolidated balance sheets as of September 30, 1995 and 1994 and the
  consolidated statements of operations and cash flows for each of the three years
  in the period ended September 30, 1995, incorporated by reference in this
  Prospectus, have been incorporated by reference herein in reliance on the report
  of Coopers & Lybrand L.L.P., independent accountants, given on the authority of
  that firm as experts in accounting and auditing.
  
        The validity of the shares of Common Stock offered hereby is being passed
  upon for the Company by Robert Rothberg, Esq., Cabot Corporation, 75 State
  Street, Boston, Massachusetts 02109. Mr. Rothberg is a Vice President and the
  General Counsel of the Company. At the time of rendering his opinion as to the
  legality of the Common Stock being registered hereunder, Mr. Rothberg had a
  substantial interest in the Company, as defined by the rules of the Securities
  and Exchange Commission, in that Mr. Rothberg owned 83,294 shares of the
  Company's Common Stock, with a fair market value of in excess of $50,000, and
  had the right to purchase an additional 20,000 shares pursuant to the Company's
  1996 Equity Incentive Plan.
  
        INDEMNIFICATION OF DIRECTORS AND OFFICERS
  
        Article Eighth (j) of the Company's Certificate of Incorporation and
  Section 14 of the Company's by-laws provide that the Company shall indemnify any
  person who was a party, is a party or is threatened to be made a party to any
  threatened, pending or completed action, suit, or proceeding by reason of the
  fact that he is or was a director, officer, employee or agent of the Company or
  is or was serving at the request of the Company as a director, officer, employee
  or agent of another company or enterprise including service as a fiduciary of an
  employee benefit plan against expenses (including attorneys' fees), judgments,
  fines, penalties and amounts paid in settlement incurred in connection with such
  action, suit or proceeding to the extent permitted from time to time under the
  Delaware General Corporation Law. Such indemnification shall be made as
  authorized in a specific case upon a determination by the Board of Directors or
  the stockholders of the Company. The rights of indemnification are not exclusive
  of any other rights to which those seeking
  
                                         -5-
  9
  
  indemnification may be entitled and shall continue as to a person who ceases to
  be a director, officer, employee or agent. In addition, under Article Eighth (i)
  no director of the Company shall be liable to the Company or its stockholders
  for monetary damages for any breach of fiduciary duty, except to the extent that
  Delaware General Corporation Law prohibits the elimination or limitation of
  liability of directors for breach of fiduciary duty.
  
        Section 145 of the Delaware General Corporation Law authorizes the
  indemnification of directors, officers, employees and agents against liability
  incurred by reason of being a director, officer, employee or agent, and against
  expenses (including attorneys' fees) in connection with defending any action
  seeking to establish liability, in the case of third-party claims, if such
  person acted in good faith and in a manner he or she reasonably believed to be
  in or not opposed to the best interests of the corporation, unless a court
  otherwise determines. Indemnification is also authorized with respect to any
  criminal action or proceeding where such person had no reasonable cause to
  believe his or her conduct was unlawful.
  
        The Company's current directors' and officers' insurance policies cover
  directors and officers of the Company and its subsidiaries.
  
                                         -6-
  10
  
  PART II  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  Item 3. Incorporation of Documents by Reference
  
        The following documents filed with the Commission are incorporated herein
  by reference:
  
        (a) The Company's Annual Report on Form 10-K, for the fiscal year ended
  September 30, 1995, filed under Section 13 of the Exchange Act.
  
        (b) The Company's Quarterly Report on Form 10-Q for the quarter ended
  December 31, 1995, filed under Section 13 of the Exchange Act.
  
        (c) The Company's Quarterly Report on Form 10-Q for the quarter ended
  March 31, 1996, filed under Section 13 of the Exchange Act.
  
        (d) The description of the Company's Common Stock contained in the
  Company's Registration Statement on Form 10 filed pursuant to Section 12 of the
  Exchange Act and the description of the Company's Preferred Stock Purchase
  Rights contained in the Company's Registration Statement on Form 8-A filed
  pursuant to Section 12 of the Exchange Act.
  
        All reports and other documents subsequently filed by the Company pursuant
  to Sections 13, 14 or 15(d) of the Exchange Act, prior to filing a
  post-effective amendment which indicates that all securities offered hereby have
  been sold or which deregisters all securities remaining unsold, shall be deemed
  incorporated by reference herein and to be part hereof from the date of the
  filing of such report and documents.
  
  Item 4. Description of Securities
  
        The Company's Common Stock is registered under Section 12 of the Exchange
  Act and the Company's Preferred Stock Purchase Rights is registered under
  Section 12 of the Exchange Act. See Item 3(d) regarding the description of the
  Company's Common Stock and the Company's Preferred Stock Purchase Rights.
  
  Item 5. Interests of Named Experts and Counsel
  
        The validity of the shares of Common Stock offered hereby is being passed
  upon for the Company by Robert Rothberg, Esq. At the time of rendering his
  opinion as to the legality of the Common Stock being registered hereunder, Mr.
  Rothberg had a substantial interest in the Company, as defined by the rules of
  the Securities and Exchange Commission, in that the fair market value of the
  83,294 shares of Common Stock beneficially owned by him exceeds $50,000, and he
  had the right to purchase an additional 20,000 shares pursuant to the Company's
  1996 Equity Incentive Plan. Also, at such time Mr. Rothberg was connected with
  the Company in that he was a Vice President and the General Counsel of the
  Company.
  
  Item 6. Indemnification of Directors and Officers
  
        Article Eighth (j) of the Company's Certificate of Incorporation and
  Section 14 of the Company's by-laws provide that the Company shall indemnify any
  person who was a party, is a party or is threatened to be made a party to any
  threatened, pending or completed action, suit, or proceeding by reason of the
  fact that he or she is or was a director, officer, employee or agent of the
  Company or is or was serving at the request of the Company as a director,
  officer, employee or agent of another company or enterprise including service as
  a fiduciary of an employee benefit plan against expenses (including attorneys'
  fees), judgments, fines, penalties and amounts paid in settlement incurred in
  connection with such action, suit or proceeding to the extent permitted from
  time to time under the Delaware General Corporation Law. Such indemnification
  shall be
           
  
                                      Page II-1
  11
  
  made as authorized in a specific case upon a determination by the Board of
  Directors or the stockholders of the Company. The rights of indemnification are
  not exclusive of any other rights to which those seeking indemnification may be
  entitled and shall continue as to a person who ceases to be a director, officer,
  employee or agent. In addition, under Article Eighth (i) no director of the
  Company shall be liable to the Company or its stockholders for monetary damages
  for any breach of fiduciary duty, except to the extent that Delaware General
  Corporation Law prohibits the elimination or limitation of liability of
  directors for breach of fiduciary duty.
  
        Section 145 of the Delaware General Corporation Law authorizes the
  indemnification of directors, officers, employees and agents against liability
  incurred by reason of being a director, officer, employee or agent, and against
  expenses (including attorneys' fees) in connection with defending any action
  seeking to establish liability, in the case of third-party claims, if such
  person acted in good faith and in a manner he or she reasonably believed to be
  in or not opposed to the best interests of the corporation, unless a court
  otherwise determines. Indemnification is also authorized with respect to any
  criminal action or proceeding where such person had no reasonable cause to
  believe his or her conduct was unlawful.
  
        The Company's current directors' and officers' insurance policies cover
  directors and officers of the Company and its subsidiaries.
  
  Item 7. Exemption from Registration Claimed
  
        Certain of the shares of Common Stock to be resold by the Selling
  Stockholders named in the Prospectus prepared in accordance with Part I of Form
  S-3 were issued by the Registrant to the Selling Stockholders pursuant to an
  exemption from registration under the Act by virtue of Section 4(2) thereof. The
  shares were issued to the Selling Stockholders pursuant to the Registrant's
  Non-Employee Directors' Stock Compensation Plan, a written plan in connection
  with the Selling Stockholders' service as outside directors for the Company. The
  Selling Stockholders had access, by virtue of their positions on the Company's
  Board of Directors, to sufficient information to make an informed investment
  decision.
  
  Item 8. Exhibits
  
        Exhibit
        Number
        ------
           5     Opinion of Robert Rothberg.
          23.1   Consent of Robert Rothberg is contained in his opinion
                 filed as Exhibit 5 to this Registration Statement.
          23.2   Consent of Coopers & Lybrand L.L.P.
          24     Power of Attorney.
          99     Non-Employee Directors' Stock Compensation Plan.
  
  Item 9. Undertakings
  
        A. Subsequent Exchange Act Documents.
  
        The undersigned registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Securities Exchange Act of 1934 (and, where applicable, each filing of an
  employee benefit plan's annual report pursuant to Section 15(d) of the
  Securities Exchange Act of 1934) that is incorporated by reference in the
  Registration Statement shall be deemed to be a new registration statement
  relating to the securities offered therein, and the offering of such securities
  at that time shall be deemed to be the initial bona fide offering thereof.
  
                                      Page II-2
  12
  
        B. To Transmit Certain Material.
  
        The undersigned registrant hereby undertakes to deliver or cause to be
  delivered with the prospectus to each person to whom the prospectus is sent or
  given, a copy of the registrant's latest annual report to stockholders furnished
  pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the
  Securities Exchange Act of 1934. Where interim financial information required to
  be presented by Article 3 of Regulation S-X is not set forth in the prospectus,
  the undersigned also undertakes to deliver, or cause to be delivered to each
  person to whom the prospectus is sent or given, the latest quarterly report that
  is specifically incorporated by reference in the prospectus to provide such
  interim financial information.
  
        C. Undertaking to Update Annually.
  
        The undersigned registrant hereby undertakes: (1) to file during any
  period in which offers or sales are made, a post-effective amendment to the
  registration statement: (i) to include any prospectus required by Section
  10(a)(3) of the Securities Act of 1933; (ii) to reflect in the prospectus any
  facts or events arising after the effective date of the registration statement
  (or the most recent post-effective amendment thereof) which, individually or in
  the aggregate, represent a fundamental change in the information set forth in
  the registration statement; and (iii) to include any material information with
  respect to the plan of distribution not previously disclosed in the registration
  statement or any material change in such information in the registration
  statement; (2) that, for the purpose of determining any liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein, and the
  offering of such securities shall be deemed to be the initial bona fide offering
  thereof; and (3) to remove from registration by means of a post-effective
  amendment any of the securities being registered which remain unsold at the
  termination of the offering. Provided, however, that if the information required
  to be included in a post-effective amendment by clauses (1)(i) and (1)(ii) of
  this paragraph is contained in periodic reports filed with or furnished to the
  Commission by the registrant pursuant to Section 13 or Section 15(d) of the
  Securities Exchange Act of 1934 that are incorporated by reference in the
  registration statement, the registrant need not file a post-effective amendment
  to provide such information.
  
        D. Indemnification.
  
        Insofar as indemnification for liabilities arising under the Securities
  Act of 1933 may be permitted to directors, officers and controlling persons of
  the registrant pursuant to the foregoing provisions, or otherwise, the
  registrant has been advised that in the opinion of the Securities and Exchange
  Commission such indemnification is against public policy as expressed in the Act
  and is, therefore, unenforceable. In the event that a claim for indemnification
  against such liabilities (other than the payment by the registrant of expenses
  incurred or paid by a director, officer or controlling person of the registrant
  in the successful defense of any action, suit or proceeding) is asserted by such
  director, officer or controlling person in connection with the securities being
  registered, the registrant will, unless in the opinion of its counsel the matter
  has been settled by controlling precedent, submit to a court of appropriate
  jurisdiction the question whether such indemnification by it is against public
  policy as expressed in the Act and will be governed by the final adjudication of
  such issue.
  
                                      Page II-3
  13
  
                                    SIGNATURES
  
        Pursuant to the requirements of the Securities Act of 1933, the Registrant
  certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form S-8 and has duly caused this Registration
  Statement to be signed on its behalf by the undersigned, thereunto duly
  authorized, in the City of Boston, and the Commonwealth of Massachusetts, 
  June XX, 1996.
  
                                            CABOT CORPORATION
  
                                            By /s/ Kenyon C. Gilson
                                               ------------------------------
                                               Kenyon C. Gilson                 
                                               Executive Vice President
                                               and Chief Financial Officer
  
        PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, THIS
  REGISTRATION STATEMENT HAS BEEN SIGNED BELOW BY THE FOLLOWING PERSONS IN THE
  CAPACITIES AND ON THE DATE INDICATED.
  
        SIGNATURE                                 TITLE                 DATE
        ---------                                 -----                 ----
  
  PRINCIPAL EXECUTIVE OFFICER
  
  /s/       *                            Chairman of the Board      June 21, 1996
  - ----------------------------------     of Directors and Chief
        (Samuel W. Bodman)               Executive Officer     
  
                                      
  PRINCIPAL FINANCIAL OFFICER
  
  /s/ Kenyon C. Gilson                   Executive Vice President   June 21, 1996
  - ----------------------------------     and Chief Financial 
        (Kenyon C. Gilson)               Officer
                             
  
  PRINCIPAL ACCOUNTING OFFICER           
  
  /s/       *                            Vice President             June 21, 1996
  - ----------------------------------     and Controller
        (Paul J. Gormisky)
  
  MAJORITY OF THE BOARD OF DIRECTORS
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Kennett F. Burnes)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Jane C. Bradley)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (John G.L. Cabot)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Arthur L. Goldstein)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Robert P. Henderson)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (Arnold S. Hiatt)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (John H. McArthur)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (John F. O'Brien)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
        (David V. Ragone)
  
                 *                       Director                   June 21, 1996
  - ----------------------------------
       (Charles P. Siess, Jr.)
  
                                    Page II-4
  14
  
        SIGNATURE                                 TITLE                 DATE
        ---------                                 -----                 ----
  
                *                        Director                   June 21, 1996
  - ----------------------------------
        (Morris Tanenbaum)
  
                *                        Director                   June 21, 1996
  - ----------------------------------
        (Lydia W. Thomas)
  
  *By /s/ CHARLES D. GERLINGER                                      June 21, 1996
      ------------------------------
          Charles D. Gerlinger
          As Attorney-in-Fact**
  
  - ---------------------
  ** By authority of Power of Attorney filed as Exhibit 24 to this Registration
  Statement
  
                                      Page II-5
  15
  
                                    EXHIBIT INDEX
  
  Exhibit
  Number                                                                   Page
  - ------                                                                   ----
  
  5           Opinion of Robert Rothberg, Vice President and
              General Counsel.
  
  23.1        Consent of Robert Rothberg is contained in the
              Opinion filed as Exhibit 5 to this Registration Statement.
  
  23.2        Consent of Coopers & Lybrand L.L.P.
  
  24          Power of Attorney.
  
  99          Non-Employee Directors' Stock Compensation Plan.
  
                                      Page II-6