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  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  
  
  
  
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt">As
  filed with the U.S. Securities and Exchange Commission on
  August&nbsp;10, 2006
  </DIV>
  
  
  <DIV align="right" style="font-size: 10pt; margin-top: 12pt">Registration No.&nbsp;333- <U>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U>
  </DIV>
  
  
  <DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>
  <DIV style="width: 100%; border-bottom: 1pt solid black; font-size: 1pt">&nbsp;</DIV>
  
  
  
  
  <DIV align="center" style="font-size: 14pt; margin-top: 12pt"><B>UNITED STATES SECURITIES AND EXCHANGE COMMISSION</B>
  </DIV>
  
  <DIV align="center" style="font-size: 12pt"><B>Washington, D.C. 20549</B>
  </DIV>
  <DIV align="center"><DIV style="font-size: 1pt; margin-top: 8pt; width: 26%; border-bottom: 1px solid #000000">&nbsp;</DIV>
  </DIV>
  <DIV align="center" style="font-size: 18pt; margin-top: 8pt"><B>FORM S-8</B>
  </DIV>
  
  <DIV align="center" style="font-size: 12pt; margin-top: 12pt"><B>REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933</B></DIV>
  
  <DIV align="center" style="font-size: 24pt; margin-top: 12pt"><B><FONT style="border-bottom: 1px solid #000000">CABOT CORPORATION</FONT></B>
  </DIV>
  
  <DIV align="center" style="font-size: 10pt">(Exact name of registrant as specified in its charter)</DIV>
  
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="47%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="47%">&nbsp;</TD>
  </TR>
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD align="center" valign="top"><B>Delaware</B>
  </TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top"><B>04-2271897</B></TD>
  </TR>
  <TR valign="bottom">
      <TD align="center" valign="top">(State or other jurisdiction
  </TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top">(I.R.S. Employer</TD>
  </TR>
  <TR valign="bottom">
      <TD align="center" valign="top">of incorporation or organization)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top">Identification No.)</TD>
  </TR>
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  <DIV align="Center" style="font-size: 10pt; margin-top: 12pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 6pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV>
  
  </DIV>
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="47%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="47%">&nbsp;</TD>
  </TR>
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD align="center" valign="top"><B>Two Seaport Lane</B></TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD align="center" valign="top"><B>Suite&nbsp;1300</B></TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD align="center" valign="top"><B>Boston, MA</B>
  </TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top"><B>02210</B></TD>
  </TR>
  <TR valign="bottom">
      <TD align="center" valign="top">(Address of principal executive offices)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="center" valign="top">(Zip Code)</TD>
  </TR>
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  <DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>1999 Equity Incentive Plan<BR>
  1996 Equity Incentive Plan</B><BR>
  (Full title of the plan)
  
  </DIV>
  
  <DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 12pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV>
  
  </DIV>
  
  <DIV align="Center" style="font-size: 10pt; margin-top: 6pt">Brian A. Berube, Esq.<BR>
  Vice President and General Counsel<BR>
  Two Seaport Lane<BR>
  Suite&nbsp;1300<BR>
  Boston, MA 02210<BR>
  <U>(Name and address of agent for service)</U>
  
  </DIV>
  
  <DIV align="Center" style="font-size: 10pt; margin-top: 10pt">617-345-0100<BR>
  <U>(Telephone number, including area code, of agent for service)</U>
  
  </DIV>
  
  <DIV align="Center" style="font-size: 10pt; margin-top: 10pt">CALCULATION OF REGISTRATION FEE
  
  </DIV>
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom" style="font-size: 3pt">
      <TD width="1%">&nbsp;</TD>
      <TD width="54%">&nbsp;</TD>
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      <TD width="2%">&nbsp;</TD>
      <TD width="7%">&nbsp;</TD>
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      <TD width="2%">&nbsp;</TD>
      <TD width="7%">&nbsp;</TD>
  
      <TD width="1%">&nbsp;</TD>
  </TR><TR style="font-size: 1px" valign="bottom">
      <TD nowrap align="left" colspan="15" style="border-bottom: 3px double #000000">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>
  
      <TD>&nbsp;</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Proposed Maximum</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Proposed Maximum</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Amount Of</TD>
      <TD width="1%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>
  
      <TD nowrap align="center">&nbsp;</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Amount To Be</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Offering Price Per</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Aggregate Offering</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Registration</TD>
      <TD width="1%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>
  
      <TD nowrap align="center">Title Of Securities To Be Registered</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Registered (1)</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Share</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Price</TD>
      <TD style="border-right: 2px solid #000000">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">Fee</TD>
      <TD width="1%">&nbsp;</TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD width="1%" style="border-top: 1px solid #000000">&nbsp;</TD>
                      <TD align="center" style="border-top: 1px solid #000000"><DIV style="margin-left:15px; text-indent:-15px">Common Stock,
  Par Value $1.00 per
  share</DIV></TD>
      <TD style="border-right: 2px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
      <TD style="border-top: 1px solid #000000">&nbsp;</TD>
  
  <TD NOWRAP align="center" valign="bottom" style="border-top: 1px solid #000000">604,700 shares (2)</TD>
      <TD style="border-right: 2px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
      <TD style="border-top: 1px solid #000000">&nbsp;</TD>
  
  <TD NOWRAP align="center" valign="bottom" style="border-top: 1px solid #000000">$26.40-$34.87 (3)</TD>
      <TD style="border-right: 2px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
      <TD style="border-top: 1px solid #000000">&nbsp;</TD>
  
  <TD NOWRAP align="center" valign="bottom" style="border-top: 1px solid #000000">$17,551,586 (3)</TD>
      <TD style="border-right: 2px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
      <TD style="border-top: 1px solid #000000">&nbsp;</TD>
  
  <TD align="center" valign="bottom" style="border-top: 1px solid #000000"><FONT style="white-space: nowrap">$1,878.02 (3)</FONT></TD>
      <TD width="1%" style="border-top: 1px solid #000000">&nbsp;</TD>
  </TR>
  <TR style="font-size: 1px" valign="bottom">
      <TD nowrap align="left" colspan="15" style="border-top: 3px double #000000">&nbsp;</TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  
  <DIV style="margin-top: 3pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  <TR>
      <TD width="3%"></TD>
      <TD width="1%"></TD>
      <TD width="96"></TD>
  </TR>
  <TR valign="top">
      <TD nowrap align="left">(1)</TD>
      <TD>&nbsp;</TD>
      <TD>Pursuant to Rule 416(a) under the Securities Act of 1933, this registration statement also
  covers such additional shares of common stock as may become issuable under the plans to
  prevent dilution from stock splits, stock dividends and similar transactions.</TD>
  </TR>
  
  <TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>
  
  <TR valign="top">
      <TD nowrap align="left">(2)</TD>
      <TD>&nbsp;</TD>
      <TD>The shares of Cabot Corporation common stock being registered hereby include (a)&nbsp;84,400
  shares issuable upon the exercise of outstanding
  stock options issued under the 1999 Equity Incentive Plan; and
  (b)&nbsp;520,300 shares issuable upon the exercise of outstanding
  stock options issued under the 1996 Equity Incentive Plan.</TD>
  </TR>
  
  <TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>
  
  <TR valign="top">
      <TD nowrap align="left">(3)</TD>
      <TD>&nbsp;</TD>
      <TD>The option exercise prices range from a low of $26.40 to a
  high of $34.87. Estimated solely for the purpose of calculating the registration fee pursuant to
  Rule 457(h) of the Securities Act of 1933, as amended, and based upon
  the prices at which the outstanding stock options may be exercised.</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  
  <DIV style="width: 100%; border-bottom: 1pt solid black; margin-top: 10pt; font-size: 1pt">&nbsp;</DIV>
  <DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>
  
  
  
  
  
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  
  
  
  
  
  
  
  
  <!-- TOC -->
  <A name="toc"><DIV align="CENTER" style="page-break-before:always"><U><B>TABLE OF CONTENTS</B></U></DIV></A>
  
  <P><CENTER>
  <TABLE border="0" width="90%" cellpadding="0" cellspacing="0">
  <TR>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="76%"></TD>
  </TR>
  <TR><TD colspan="9"><A HREF="#000">PART II</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#001">Item&nbsp;3. Incorporation of Documents by Reference</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#002">Item&nbsp;5. Interests of Named Experts and Counsel</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#003">Item&nbsp;6. Indemnification of Directors and Officers</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#004">Item&nbsp;8. Exhibits</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#005">Item&nbsp;9. Undertakings</A></TD></TR>
  <TR><TD colspan="9"><A HREF="#006">SIGNATURES</A></TD></TR>
  <TR><TD colspan="9"><A HREF="#007">EXHIBIT INDEX</A></TD></TR>
  <TR><TD colspan="9"><A HREF="b61824ccexv5w1.htm">EX-5.1 Opinion of Brian A. Berube</A></TD></TR>
  <TR><TD colspan="9"><A HREF="b61824ccexv23w1.htm">EX-23.1 Consent of PricewaterhouseCoopers LLP</A></TD></TR>
  </TABLE>
  </CENTER>
  <!-- /TOC -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  
  
  
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>REGISTRATION OF ADDITIONAL SHARES PURSUANT TO GENERAL INSTRUCTION E</B>
  </DIV>
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Cabot Corporation, Inc. (&#147;Registrant&#148;) is filing this registration statement on Form S-8 to
  register 84,400 additional shares of Registrant&#146;s common stock issuable upon the exercise of outstanding
  stock options issued under
  Registrant&#146;s 1999 Equity Incentive Plan (the &#147;1999
  Plan&#148;) and 520,300 additional shares of
  Registrant&#146;s common stock issuable upon the exercise of outstanding
  stock options issued under Registrant&#146;s 1996 Equity Incentive Plan
  (the &#147;1996 Plan&#148;).
  </DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;On July&nbsp;6, 1999 and July&nbsp;22, 2002, Registrant filed registration statements on Form S-8 (file
  nos. 333-82353 and 333-96879, respectively) with the United States Securities and Exchange
  Commission (&#147;SEC&#148;) to register shares of Registrant&#146;s common stock for issuance under the 1999 Plan
  (the &#147;1999 Plan Registration Statement&#148;). On May&nbsp;14, 1996, Registrant filed a registration
  statement on Form S-8 (file no. 333-03683) with the SEC to register shares of Registrant&#146;s common
  stock for issuance under the 1996 Plan (the &#147;1996 Plan Registration Statement&#148;). In accordance
  with General Instruction E of Form S-8, the contents of the 1999 Plan Registration Statement and
  the 1996 Plan Registration Statement are hereby incorporated into this registration statement.
  </DIV>
  <!-- link1 "PART II" -->
  <DIV align="left"><A NAME="000"></A></DIV>
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>PART II<BR>
  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT</B>
  </DIV>
  
  <!-- link2 "Item&nbsp;3. Incorporation of Documents by Reference" -->
  <DIV align="left"><A NAME="001"></A></DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;3. Incorporation of Documents by Reference.</B>
  </DIV>
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following documents filed with the Securities and Exchange Commission (the &#147;Commission&#148;)
  pursuant to the Securities Exchange Act of 1934, as amended (the &#147;Exchange Act&#148;) by Cabot
  Corporation (the &#147;Registrant&#148;) (Commission File No.&nbsp;1-5667) are incorporated in this Registration
  Statement by reference and shall be deemed to be a part hereof:
  </DIV>
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(a)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The Registrant&#146;s Annual Report on Form 10-K for the fiscal year ended September
  30, 2005, as filed with the Commission on December&nbsp;14, 2005;</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(b)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The Registrant&#146;s Quarterly Report on Form 10-Q for the quarterly period ended
  December&nbsp;31, 2005, as filed with the Commission on February&nbsp;9, 2006;</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(c)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The Registrant&#146;s Quarterly Report on Form 10-Q for the quarterly period ended
  March&nbsp;31, 2006, as filed with the Commission on May&nbsp;10, 2006;</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(d)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The Registrant&#146;s Quarterly Report on Form 10-Q for the quarterly period ended
  June&nbsp;30, 2006, as filed with the Commission on August&nbsp;9,
  2006;</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(e)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The Registrant&#146;s Current Reports on Form 8-K as filed with the Commission on
  August&nbsp;10, 2006, August&nbsp;3, 2006, July&nbsp;20, 2006, July&nbsp;14, 2006, June&nbsp;1, 2006, May&nbsp;17, 2006, May&nbsp;4, 2006,
  February&nbsp;9, 2006, February&nbsp;2, 2006, January&nbsp;19, 2006, January&nbsp;10, 2006, December&nbsp;27,
  2005, December&nbsp;13, 2005, November&nbsp;23, 2005, November&nbsp;3, 2005, and October&nbsp;17, 2005;</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(e)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The description of the Registrant&#146;s Common Stock, $1.00 par value per share,
  contained in the Registrant&#146;s Registration Statement on Form&nbsp;10, filed with the
  Commission pursuant to Section&nbsp;12 of the Exchange Act.</TD>
  </TR>
  
  </TABLE>
  </DIV>
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <DIV style="margin-top: 6pt"><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  
  
  </TABLE>
  </DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;All documents subsequently filed by the Registrant pursuant to Sections&nbsp;13(a), 13(c), 14 and
  15(d) of the Exchange Act, prior to the filing of a post-effective amendment to this Registration
  Statement that indicates that all securities offered have been sold or which deregisters all
  securities then remaining unsold, shall be deemed to be incorporated herein by reference from the
  date of filing of such documents. Any statement contained in this Registration Statement, in an
  amendment hereto or in a document incorporated or deemed to be incorporated by reference herein
  shall be deemed to be modified or superseded for the purposes of this Registration Statement to the
  extent that a statement contained herein or in any other subsequently filed document that also is
  or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any
  statement so modified or superseded shall not be deemed, except as so modified or superseded, to
  constitute a part of this Registration Statement.
  </DIV>
  <!-- link2 "Item&nbsp;5. Interests of Named Experts and Counsel" -->
  <DIV align="left"><A NAME="002"></A></DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;5. Interests of Named Experts and Counsel.</B>
  </DIV>
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Brian A. Berube, the Registrant&#146;s Vice President and General Counsel, has opined as to the
  legality of the issuance of the common stock being registered under this Registration Statement.
  At the time of rendering his opinion, Mr.&nbsp;Berube had a substantial interest in the Registrant, as
  defined by the rules of the Commission, in that the fair market value of Cabot common stock owned
  by him exceeds $50,000. It is anticipated that additional shares will be issued to Mr.&nbsp;Berube
  pursuant to the Cabot Corporation 2006 Long-Term Incentive Plan and under employee benefit plans of
  the Registrant.
  </DIV>
  <!-- link2 "Item&nbsp;6. Indemnification of Directors and Officers" -->
  <DIV align="left"><A NAME="003"></A></DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;6. Indemnification of Directors and Officers.</B>
  </DIV>
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Section&nbsp;145 of the Delaware General Corporation Law, as amended, provides that a corporation
  may indemnify any person who was or is a party or is threatened to be made a party to any threatened,
  pending or completed action, suit or proceeding, whether civil, criminal or investigative (other
  than an action by or in the right of the corporation) by reason of the fact that such person is or
  was a director, officer, employee or agent of the corporation, or is or was serving at the request
  of the corporation as director, officer, employee or agent of another corporation, partnership,
  joint venture, trust or other enterprise, against expenses (including attorneys&#146; fees), judgments,
  fines and amounts paid in settlement actually and reasonably incurred by such person in connection
  with such action, suit or proceeding if such person acted in good faith and in a manner such person
  reasonably believed to be in or not opposed to the best interests of the corporation, and, with
  respect to any criminal action or proceeding, had no reasonable cause to believe such person&#146;s
  conduct was unlawful. Section&nbsp;145 further provides that a corporation similarly may indemnify any
  such person serving in any such capacity who was or is a party or is threatened to be made a party
  to any threatened, pending or completed action or suit by or in the right of the corporation to
  procure a judgment in its favor, against expenses actually and reasonably incurred in connection
  with the defense or settlement of such action or suit if such person acted in good faith and in a
  manner such person reasonably believed to be in or not opposed to the best interest of the
  corporation and except that no indemnification shall be made in respect of any claim, issue or
  matter as to which such person shall have been adjudged to be liable to the corporation unless and
  only to the extent that the Delaware Court of Chancery or such other court in which such action or
  suit was brought shall determine upon application that, despite the adjudication of liability but
  in view of all the circumstances of the case, such person is fairly and reasonably entitled to
  indemnity for such expenses which the Court of Chancery or such other court shall deem proper.
  </DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Section&nbsp;102(b)(7) of the Delaware General Corporation Law, as amended, permits a corporation
  to include in its certificate of incorporation a provision eliminating or limiting the personal
  liability of a director to the corporation or its stockholders for monetary damages for breach of
  fiduciary duty as a director, provided, however,
  </DIV>
  
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">that such provision shall not eliminate or limit the liability of a director (i)&nbsp;for any
  breach of the director&#146;s duty of loyalty to the corporation or its stockholders, (ii)&nbsp;for acts or
  omissions not in good faith or which involve intentional misconduct or a knowing violation of law,
  (iii)&nbsp;under Section&nbsp;174 of the Delaware General Corporation Law (relating to unlawful payment of
  dividends and unlawful stock purchase and redemption) or (iv)&nbsp;for any transaction from which the
  director derived an improper personal benefit.
  </DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Article&nbsp;Eight (j)&nbsp;of the Registrant&#146;s Certificate of Incorporation and Section&nbsp;14 of the
  Registrant&#146;s by-laws provide that the Registrant 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 such person is or was a director, officer, employee or agent
  of the Registrant or is or was serving at the request of the Registrant 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&#146; 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 Registrant. 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&nbsp;Eight (i)&nbsp;of the
  Registrant&#146;s Certificate of Incorporation no director or officer of the Registrant shall be liable
  to the Registrant 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 or officers for breach of fiduciary duty.
  </DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;All of the Registrant&#146;s directors and officers are covered by insurance policies maintained by
  the Registrant against specified liabilities for actions taken in their capacities as such,
  including liabilities under the Securities Act.
  </DIV>
  <!-- link2 "Item&nbsp;8. Exhibits" -->
  <DIV align="left"><A NAME="004"></A></DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;8. Exhibits.</B>
  </DIV>
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="9%">&nbsp;</TD>
      <TD width="3%">&nbsp;</TD>
      <TD width="88%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left">Exhibit</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Number</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" style="border-bottom: 1px solid #000000">Document Description</TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Restated Certificate of Incorporation of Cabot Corporation (incorporated by
  reference to Exhibit&nbsp;3.1 to the Quarterly Report on Form&nbsp;10-Q of Cabot Corporation,
  File No.&nbsp;1-5667, filed with the Commission on February&nbsp;9, 2006).</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Opinion of Brian A. Berube, Vice President and General Counsel.</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of PricewaterhouseCoopers LLP.</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of Brian A. Berube, Vice President and General Counsel (included in Exhibit&nbsp;5.1).</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Power of Attorney (included on the signature page of this registration statement).</TD>
  </TR>
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  
  <DIV align="left">
  <DIV style="font-size: 1pt; margin-top: 6pt; width: 18%; border-bottom: 1px solid #000000">&nbsp;</DIV>
  </DIV>
  
  <DIV style="margin-top: 3pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  <TR>
      <TD width="3%"></TD>
      <TD width="1%"></TD>
      <TD width="96"></TD>
  </TR>
  <TR valign="top">
      <TD nowrap align="left">*</TD>
      <TD>&nbsp;</TD>
      <TD>Filed herewith</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  <!-- link2 "Item&nbsp;9. Undertakings" -->
  <DIV align="left"><A NAME="005"></A></DIV>
  
  <DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;9. Undertakings.</B>
  </DIV>
  
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(a)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The undersigned Registrant hereby undertakes:</TD>
  </TR>
  
  </TABLE>
  </DIV>
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <DIV style="margin-top: 6pt"><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  
  
  </TABLE>
  </DIV>
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="6%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(1)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>To file, during any period in which offers or sales are being
  made, a post-effective amendment to this Registration Statement:</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="10%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(i)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>To include any prospectus required by Section
  10(a)(3) of the Securities Act;</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="10%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(ii)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>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</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="10%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(iii)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>To include any material information with
  respect to the plan of distribution not previously disclosed in the
  Registration Statement or any material change to such information in
  the Registration Statement;</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="6%" style="background: transparent">&nbsp;</TD>
      <TD colspan="3"><I>provided, however</I>, that paragraphs (a)(1)(i) and (a)(1)(ii) above shall not apply if
  the information required to be included in a post-effective amendment by those
  paragraphs is contained in reports filed with or furnished to the Commission by the
  Registrant pursuant to Section&nbsp;13 or 15(d) of the Exchange Act that are incorporated
  by reference in the Registration Statement.</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="6%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(2)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>That, for the purpose of determining any liability under the
  Securities Act, 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 at that time shall be deemed to be the initial <I>bona
  fide </I>offering thereof.</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="6%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(3)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>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.</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  <DIV style="margin-top: 6pt">
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(b)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>The undersigned Registrant hereby undertakes that, for purposes of determining
  any liability under the Securities Act, each filing of the Registrant&#146;s annual report
  pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each
  filing of an employee benefit plan&#146;s annual report pursuant to Section 15(d) of the
  Exchange Act) 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 <I>bona
  fide </I>offering thereof.</TD>
  </TR>
  
  <TR>
      <TD style="font-size: 6pt">&nbsp;</TD>
  </TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">(c)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Insofar as indemnification for liabilities arising under the Securities Act 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 Commission such indemnification is against public policy as expressed in
  the Securities 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</TD>
  </TR>
  
  </TABLE>
  </DIV>
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <DIV style="margin-top: 6pt"><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  <TR valign="top" style="font-size: 10pt; color: #textcolor#; background: #bgcolor#">
      <TD width="2%" style="background: transparent">&nbsp;</TD>
      <TD width="3%" nowrap align="left">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>by it is against public policy as expressed in the Securities Act and will be
  governed by the final adjudication of such issue.</TD>
  </TR>
  
  </TABLE>
  </DIV>
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <DIV style="margin-top: 6pt"><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  
  
  </TABLE>
  </DIV>
  <!-- link1 "SIGNATURES" -->
  <DIV align="left"><A NAME="006"></A></DIV>
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>SIGNATURES</B>
  </DIV>
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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, The Commonwealth of Massachusetts, on this
  9<SUP style="font-size: 85%; vertical-align: text-top">th</SUP> day of August, 2006.
  </DIV>
  
  <TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
  <TR>
      <TD width="48%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="35%">&nbsp;</TD>
      <TD width="15%">&nbsp;</TD>
  </TR>
  <TR>
      <TD valign="top" align="left">&nbsp;</TD>
      <TD colspan="3" align="left"><FONT style="font-variant: SMALL-CAPS">CABOT CORPORATION </FONT><BR>
  &nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR><TR>
      <TD align="left">&nbsp;</TD>
      <TD valign="top">By:&nbsp;&nbsp;</TD>
      <TD colspan="2" style="border-bottom: 1px solid #000000" align="left"><FONT style="font-variant: SMALL-CAPS">/s/ Kennett F. Burnes</FONT>
  &nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR><TR>
      <TD align="left">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD valign="top">Name:&nbsp;&nbsp;</TD>
      <TD align="left">Kennett F. Burnes&nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR><TR>
      <TD align="left">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD valign="top">Title:&nbsp;&nbsp;</TD>
      <TD align="left">President and Chief Executive Officer&nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR>
  <TR>
      <TD colspan="5">&nbsp;</TD>
  </TR>
  </TABLE>
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>SIGNATURES AND POWER OF ATTORNEY</B>
  </DIV>
  
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Each person whose signature appears below constitutes and appoints Brian A. Berube and Jane A.
  Bell and each of them singly, his or her true and lawful attorney-in-fact and agent with full power
  of substitution and resubstitution, for him or her and in his or her name, place and stead as a
  director or officer or both, as the case may be, of Cabot Corporation, to sign any and all
  amendments (including post-effective amendments) to this Registration Statement on Form S-8 to be
  filed by Cabot Corporation, and all documents or instruments necessary or appropriate to enable
  Cabot Corporation to comply with the Securities Act of 1933, as amended, and to file the same, with
  all exhibits thereto, with the Securities and Exchange Commission, granting unto said
  attorneys-in-fact and agents full power and authority to do and perform each and every act
  whatsoever that is necessary, appropriate or advisable in connection with any or all of the
  above-described matters and to all intents and purposes as he or she might or could do in person,
  hereby ratifying and confirming all that said attorneys-in-fact and agents, or their substitutes,
  may lawfully do or cause to be done by virtue hereof.
  </DIV>
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt">* * * *
  </DIV>
  
  
  <DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant to the requirements of the Securities Act of 1933, as amended, this registration
  statement has been signed by the following persons in the capacities and on the dates indicated.
  </DIV>
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="35%">&nbsp;</TD>
      <TD width="2%">&nbsp;</TD>
      <TD width="40%">&nbsp;</TD>
      <TD width="2%">&nbsp;</TD>
      <TD width="12%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Signature</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Title</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Date</TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD align="left" valign="top">/s/ Kennett F. Burnes
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Kennett F. Burnes</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director, Chairman of the Board, Chief
  <BR>
  Executive Officer and President<br>
  (Principal Executive Officer)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Jonathan P. Mason
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  J<FONT style="font-variant: SMALL-CAPS">onathan </FONT>P. M<FONT style="font-variant: SMALL-CAPS">ason</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Executive Vice President and Chief
  Financial Officer<br>
  (Principal Financial Officer)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ James P. Kelly
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  J<FONT style="font-variant: SMALL-CAPS">ames </FONT>P. K<FONT style="font-variant: SMALL-CAPS">elly</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Controller<br>
  (Controller/Principal Accounting Officer)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Dirk L. Blevi <FONT style="font-variant: SMALL-CAPS">  </FONT>
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  DIRK L. BLEVI</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="35%">&nbsp;</TD>
      <TD width="2%">&nbsp;</TD>
      <TD width="40%">&nbsp;</TD>
      <TD width="2%">&nbsp;</TD>
      <TD width="12%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Signature</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Title</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Date</TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ John S. Clarkeson
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  J<FONT style="font-variant: SMALL-CAPS">ohn </FONT>S. C<FONT style="font-variant: SMALL-CAPS">larkeson</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Juan Enriquez-Cabot
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  J<FONT style="font-variant: SMALL-CAPS">uan </FONT>E<FONT style="font-variant: SMALL-CAPS">nriquez-</FONT>C<FONT style="font-variant: SMALL-CAPS">abot</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Arthur L. Goldstein
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Arthur L. Goldstein</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Gautam S. Kaji
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Gautam S. Kaji</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Roderick C.G. MacLeod
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Roderick C.G. Macleod</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ John H. McArthur
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">John H. McArthur</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Henry F. McCance
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Henry </FONT>F. M<FONT style="font-variant: SMALL-CAPS">cCance</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ John F. O&#146;Brien
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">John F. O&#146;Brien</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Ronaldo H. Schmitz
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Ronaldo H. Schmitz</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Lydia W. Thomas
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Lydia W. Thomas</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Mark S. Wrighton
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Mark S. Wrighton</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <TR valign="bottom" style="padding-top: 1em">
      <TD align="left" valign="top">/s/ Shengman Zhang
  <DIV style="font-size: 1pt; border-bottom: 1px solid #000000">&nbsp;</DIV>
  <FONT style="font-variant: SMALL-CAPS">Shengman zhang</FONT></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">August 9, 2006</TD>
  </TR>
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  <!-- link1 "EXHIBIT INDEX" -->
  <DIV align="left"><A NAME="007"></A></DIV>
  
  <DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>EXHIBIT INDEX</B>
  </DIV>
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="9%">&nbsp;</TD>
      <TD width="3%">&nbsp;</TD>
      <TD width="88%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left">Exhibit</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left" style="border-bottom: 1px solid #000000">Number</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" style="border-bottom: 1px solid #000000">Document Description</TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Restated Certificate of Incorporation of Cabot Corporation (incorporated by
  reference to Exhibit&nbsp;3.1 to the Quarterly Report on Form&nbsp;10-Q of Cabot Corporation,
  File No.&nbsp;1-5667, filed with the Commission on February&nbsp;9, 2006).</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Opinion of Brian A. Berube, Vice President and General Counsel.</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of PricewaterhouseCoopers LLP.</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of Brian A. Berube, Vice President and General Counsel (included in Exhibit&nbsp;5.1).</TD>
  </TR>
  <TR valign="bottom"><!-- Blank Space -->
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24*
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Power of Attorney (included on the signature page of this registration statement).</TD>
  </TR>
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
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  <DIV style="font-size: 3pt; margin-top: 6pt; width: 18%; border-bottom: 1px solid #000000">&nbsp;</DIV>
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      <TD width="96"></TD>
  </TR>
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      <TD nowrap align="left">*</TD>
      <TD>&nbsp;</TD>
      <TD>Filed herewith</TD>
  </TR>
  
  </TABLE>
  </DIV>
  
  <P align="center" style="font-size: 10pt">&nbsp;
  </DIV>
  
  </BODY>
  </HTML>
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "b61824ccsv8.htm", "description": "CABOT CORPORATION", "secsgml_size_bytes": 54551}]
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": "333-136484", "film-number": "061021079"}, "business-address": {"street1": "TWO SEAPORT LANE SUITE 1300", "city": "BOSTON", "state": "MA", "zip": "02109-1806", "phone": "6173450100"}, "mail-address": {"street1": "TWO SEAPORT LANE SUITE 1300", "city": "BOSTON", "state": "MA", "zip": "82109"}, "former-company": {"former-conformed-name": "CABOT GODFREY L INC", "date-changed": "19680418"}}
text: sv8
  Table of Contents
  As
  filed with the U.S. Securities and Exchange Commission on
  August 10, 2006
  Registration No. 333-
  UNITED STATES 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
  (I.R.S. Employer
  of incorporation or organization)
  Identification No.)
  Two Seaport Lane
  Suite 1300
  Boston, MA
  02210
  (Address of principal executive offices)
  (Zip Code)
  1999 Equity Incentive Plan
  1996 Equity Incentive Plan
  (Full title of the plan)
  Brian A. Berube, Esq.
  Vice President and General Counsel
  Two Seaport Lane
  Suite 1300
  Boston, MA 02210
  (Name and address of agent for service)
  617-345-0100
  (Telephone number, including area code, of agent for service)
  CALCULATION OF REGISTRATION FEE
  Proposed Maximum
  Proposed Maximum
  Amount Of
  Amount To Be
  Offering Price Per
  Aggregate Offering
  Registration
  Title Of Securities To Be Registered
  Registered (1)
  Share
  Price
  Fee
  Common Stock,
  Par Value $1.00 per
  share
  604,700 shares (2)
  $26.40-$34.87 (3)
  $17,551,586 (3)
  $1,878.02 (3)
  (1)
  Pursuant to Rule 416(a) under the Securities Act of 1933, this registration statement also
  covers such additional shares of common stock as may become issuable under the plans to
  prevent dilution from stock splits, stock dividends and similar transactions.
  (2)
  The shares of Cabot Corporation common stock being registered hereby include (a) 84,400
  shares issuable upon the exercise of outstanding
  stock options issued under the 1999 Equity Incentive Plan; and
  (b) 520,300 shares issuable upon the exercise of outstanding
  stock options issued under the 1996 Equity Incentive Plan.
  (3)
  The option exercise prices range from a low of $26.40 to a
  high of $34.87. Estimated solely for the purpose of calculating the registration fee pursuant to
  Rule 457(h) of the Securities Act of 1933, as amended, and based upon
  the prices at which the outstanding stock options may be exercised.
  TABLE OF CONTENTS
  PART II
  Item 3. Incorporation of Documents by Reference
  Item 5. Interests of Named Experts and Counsel
  Item 6. Indemnification of Directors and Officers
  Item 8. Exhibits
  Item 9. Undertakings
  SIGNATURES
  EXHIBIT INDEX
  EX-5.1 Opinion of Brian A. Berube
  EX-23.1 Consent of PricewaterhouseCoopers LLP
  Table of Contents
  REGISTRATION OF ADDITIONAL SHARES PURSUANT TO GENERAL INSTRUCTION E
  Cabot Corporation, Inc. ("Registrant") is filing this registration statement on Form S-8 to
  register 84,400 additional shares of Registrant's common stock issuable upon the exercise of outstanding
  stock options issued under
  Registrant's 1999 Equity Incentive Plan (the "1999
  Plan") and 520,300 additional shares of
  Registrant's common stock issuable upon the exercise of outstanding
  stock options issued under Registrant's 1996 Equity Incentive Plan
  (the "1996 Plan").
  On July 6, 1999 and July 22, 2002, Registrant filed registration statements on Form S-8 (file
  nos. 333-82353 and 333-96879, respectively) with the United States Securities and Exchange
  Commission ("SEC") to register shares of Registrant's common stock for issuance under the 1999 Plan
  (the "1999 Plan Registration Statement"). On May 14, 1996, Registrant filed a registration
  statement on Form S-8 (file no. 333-03683) with the SEC to register shares of Registrant's common
  stock for issuance under the 1996 Plan (the "1996 Plan Registration Statement"). In accordance
  with General Instruction E of Form S-8, the contents of the 1999 Plan Registration Statement and
  the 1996 Plan Registration Statement are hereby incorporated into this registration statement.
  PART II
  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  Item 3. Incorporation of Documents by Reference.
  The following documents filed with the Securities and Exchange Commission (the "Commission")
  pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange Act") by Cabot
  Corporation (the "Registrant") (Commission File No. 1-5667) are incorporated in this Registration
  Statement by reference and shall be deemed to be a part hereof:
  (a)
  The Registrant's Annual Report on Form 10-K for the fiscal year ended September
  30, 2005, as filed with the Commission on December 14, 2005;
  (b)
  The Registrant's Quarterly Report on Form 10-Q for the quarterly period ended
  December 31, 2005, as filed with the Commission on February 9, 2006;
  (c)
  The Registrant's Quarterly Report on Form 10-Q for the quarterly period ended
  March 31, 2006, as filed with the Commission on May 10, 2006;
  (d)
  The Registrant's Quarterly Report on Form 10-Q for the quarterly period ended
  June 30, 2006, as filed with the Commission on August 9,
  2006;
  (e)
  The Registrant's Current Reports on Form 8-K as filed with the Commission on
  August 10, 2006, August 3, 2006, July 20, 2006, July 14, 2006, June 1, 2006, May 17, 2006, May 4, 2006,
  February 9, 2006, February 2, 2006, January 19, 2006, January 10, 2006, December 27,
  2005, December 13, 2005, November 23, 2005, November 3, 2005, and October 17, 2005;
  (e)
  The description of the Registrant's Common Stock, $1.00 par value per share,
  contained in the Registrant's Registration Statement on Form 10, filed with the
  Commission pursuant to Section 12 of the Exchange Act.
  Table of Contents
  All documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and
  15(d) of the Exchange Act, prior to the filing of a post-effective amendment to this Registration
  Statement that indicates that all securities offered have been sold or which deregisters all
  securities then remaining unsold, shall be deemed to be incorporated herein by reference from the
  date of filing of such documents. Any statement contained in this Registration Statement, in an
  amendment hereto or in a document incorporated or deemed to be incorporated by reference herein
  shall be deemed to be modified or superseded for the purposes of this Registration Statement to the
  extent that a statement contained herein or in any other subsequently filed document that also is
  or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any
  statement so modified or superseded shall not be deemed, except as so modified or superseded, to
  constitute a part of this Registration Statement.
  Item 5. Interests of Named Experts and Counsel.
  Brian A. Berube, the Registrant's Vice President and General Counsel, has opined as to the
  legality of the issuance of the common stock being registered under this Registration Statement.
  At the time of rendering his opinion, Mr. Berube had a substantial interest in the Registrant, as
  defined by the rules of the Commission, in that the fair market value of Cabot common stock owned
  by him exceeds $50,000. It is anticipated that additional shares will be issued to Mr. Berube
  pursuant to the Cabot Corporation 2006 Long-Term Incentive Plan and under employee benefit plans of
  the Registrant.
  Item 6. Indemnification of Directors and Officers.
  Section 145 of the Delaware General Corporation Law, as amended, provides that a corporation
  may indemnify any person who was or is a party or is threatened to be made a party to any threatened,
  pending or completed action, suit or proceeding, whether civil, criminal or investigative (other
  than an action by or in the right of the corporation) by reason of the fact that such person is or
  was a director, officer, employee or agent of the corporation, or is or was serving at the request
  of the corporation as director, officer, employee or agent of another corporation, partnership,
  joint venture, trust or other enterprise, against expenses (including attorneys' fees), judgments,
  fines and amounts paid in settlement actually and reasonably incurred by such person in connection
  with such action, suit or proceeding if such person acted in good faith and in a manner such person
  reasonably believed to be in or not opposed to the best interests of the corporation, and, with
  respect to any criminal action or proceeding, had no reasonable cause to believe such person's
  conduct was unlawful. Section 145 further provides that a corporation similarly may indemnify any
  such person serving in any such capacity who was or is a party or is threatened to be made a party
  to any threatened, pending or completed action or suit by or in the right of the corporation to
  procure a judgment in its favor, against expenses actually and reasonably incurred in connection
  with the defense or settlement of such action or suit if such person acted in good faith and in a
  manner such person reasonably believed to be in or not opposed to the best interest of the
  corporation and except that no indemnification shall be made in respect of any claim, issue or
  matter as to which such person shall have been adjudged to be liable to the corporation unless and
  only to the extent that the Delaware Court of Chancery or such other court in which such action or
  suit was brought shall determine upon application that, despite the adjudication of liability but
  in view of all the circumstances of the case, such person is fairly and reasonably entitled to
  indemnity for such expenses which the Court of Chancery or such other court shall deem proper.
  Section 102(b)(7) of the Delaware General Corporation Law, as amended, permits a corporation
  to include in its certificate of incorporation a provision eliminating or limiting the personal
  liability of a director to the corporation or its stockholders for monetary damages for breach of
  fiduciary duty as a director, provided, however,
  Table of Contents
  that such provision shall not eliminate or limit the liability of a director (i) for any
  breach of the director's duty of loyalty to the corporation or its stockholders, (ii) for acts or
  omissions not in good faith or which involve intentional misconduct or a knowing violation of law,
  (iii) under Section 174 of the Delaware General Corporation Law (relating to unlawful payment of
  dividends and unlawful stock purchase and redemption) or (iv) for any transaction from which the
  director derived an improper personal benefit.
  Article Eight (j) of the Registrant's Certificate of Incorporation and Section 14 of the
  Registrant's by-laws provide that the Registrant 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 such person is or was a director, officer, employee or agent
  of the Registrant or is or was serving at the request of the Registrant 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 Registrant. 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 Eight (i) of the
  Registrant's Certificate of Incorporation no director or officer of the Registrant shall be liable
  to the Registrant 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 or officers for breach of fiduciary duty.
  All of the Registrant's directors and officers are covered by insurance policies maintained by
  the Registrant against specified liabilities for actions taken in their capacities as such,
  including liabilities under the Securities Act.
  Item 8. Exhibits.
  Exhibit
  Number
  Document Description
  4.1
  Restated Certificate of Incorporation of Cabot Corporation (incorporated by
  reference to Exhibit 3.1 to the Quarterly Report on Form 10-Q of Cabot Corporation,
  File No. 1-5667, filed with the Commission on February 9, 2006).
  5.1*
  Opinion of Brian A. Berube, Vice President and General Counsel.
  23.1*
  Consent of PricewaterhouseCoopers LLP.
  23.2*
  Consent of Brian A. Berube, Vice President and General Counsel (included in Exhibit 5.1).
  24*
  Power of Attorney (included on the signature page of this registration statement).
  *
  Filed herewith
  Item 9. Undertakings.
  (a)
  The undersigned Registrant hereby undertakes:
  Table of Contents
  (1)
  To file, during any period in which offers or sales are being
  made, a post-effective amendment to this Registration Statement:
  (i)
  To include any prospectus required by Section
  10(a)(3) of the Securities Act;
  (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 to such information in
  the Registration Statement;
  provided, however
  , that paragraphs (a)(1)(i) and (a)(1)(ii) above shall not apply if
  the information required to be included in a post-effective amendment by those
  paragraphs is contained in reports filed with or furnished to the Commission by the
  Registrant pursuant to Section 13 or 15(d) of the Exchange Act that are incorporated
  by reference in the Registration Statement.
  (2)
  That, for the purpose of determining any liability under the
  Securities Act, 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 at that time shall be deemed to be the initial
  bona
  fide
  offering thereof.
  (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.
  (b)
  The undersigned Registrant hereby undertakes that, for purposes of determining
  any liability under the Securities Act, each filing of the Registrant's annual report
  pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each
  filing of an employee benefit plan's annual report pursuant to Section 15(d) of the
  Exchange Act) 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.
  (c)
  Insofar as indemnification for liabilities arising under the Securities Act 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 Commission such indemnification is against public policy as expressed in
  the Securities 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
  Table of Contents
  by it is against public policy as expressed in the Securities Act and will be
  governed by the final adjudication of such issue.
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  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, The Commonwealth of Massachusetts, on this
  9
  th
  day of August, 2006.
  CABOT CORPORATION
  By:
  /s/ Kennett F. Burnes
  Name:
  Kennett F. Burnes
  Title:
  President and Chief Executive Officer
  SIGNATURES AND POWER OF ATTORNEY
  Each person whose signature appears below constitutes and appoints Brian A. Berube and Jane A.
  Bell and each of them singly, his or her true and lawful attorney-in-fact and agent with full power
  of substitution and resubstitution, for him or her and in his or her name, place and stead as a
  director or officer or both, as the case may be, of Cabot Corporation, to sign any and all
  amendments (including post-effective amendments) to this Registration Statement on Form S-8 to be
  filed by Cabot Corporation, and all documents or instruments necessary or appropriate to enable
  Cabot Corporation to comply with the Securities Act of 1933, as amended, and to file the same, with
  all exhibits thereto, with the Securities and Exchange Commission, granting unto said
  attorneys-in-fact and agents full power and authority to do and perform each and every act
  whatsoever that is necessary, appropriate or advisable in connection with any or all of the
  above-described matters and to all intents and purposes as he or she might or could do in person,
  hereby ratifying and confirming all that said attorneys-in-fact and agents, or their substitutes,
  may lawfully do or cause to be done by virtue hereof.
  * * * *
  Pursuant to the requirements of the Securities Act of 1933, as amended, this registration
  statement has been signed by the following persons in the capacities and on the dates indicated.
  Signature
  Title
  Date
  /s/ Kennett F. Burnes
  Kennett F. Burnes
  Director, Chairman of the Board, Chief
  Executive Officer and President
  (Principal Executive Officer)
  August 9, 2006
  /s/ Jonathan P. Mason
  J
  onathan
  P. M
  ason
  Executive Vice President and Chief
  Financial Officer
  (Principal Financial Officer)
  August 9, 2006
  /s/ James P. Kelly
  J
  ames
  P. K
  elly
  Controller
  (Controller/Principal Accounting Officer)
  August 9, 2006
  /s/ Dirk L. Blevi
  DIRK L. BLEVI
  Director
  August 9, 2006
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  Signature
  Title
  Date
  /s/ John S. Clarkeson
  J
  ohn
  S. C
  larkeson
  Director
  August 9, 2006
  /s/ Juan Enriquez-Cabot
  J
  uan
  E
  nriquez-
  C
  abot
  Director
  August 9, 2006
  /s/ Arthur L. Goldstein
  Arthur L. Goldstein
  Director
  August 9, 2006
  /s/ Gautam S. Kaji
  Gautam S. Kaji
  Director
  August 9, 2006
  /s/ Roderick C.G. MacLeod
  Roderick C.G. Macleod
  Director
  August 9, 2006
  /s/ John H. McArthur
  John H. McArthur
  Director
  August 9, 2006
  /s/ Henry F. McCance
  Henry
  F. M
  cCance
  Director
  August 9, 2006
  /s/ John F. O'Brien
  John F. O'Brien
  Director
  August 9, 2006
  /s/ Ronaldo H. Schmitz
  Ronaldo H. Schmitz
  Director
  August 9, 2006
  /s/ Lydia W. Thomas
  Lydia W. Thomas
  Director
  August 9, 2006
  /s/ Mark S. Wrighton
  Mark S. Wrighton
  Director
  August 9, 2006
  /s/ Shengman Zhang
  Shengman zhang
  Director
  August 9, 2006
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  EXHIBIT INDEX
  Exhibit
  Number
  Document Description
  4.1
  Restated Certificate of Incorporation of Cabot Corporation (incorporated by
  reference to Exhibit 3.1 to the Quarterly Report on Form 10-Q of Cabot Corporation,
  File No. 1-5667, filed with the Commission on February 9, 2006).
  5.1*
  Opinion of Brian A. Berube, Vice President and General Counsel.
  23.1*
  Consent of PricewaterhouseCoopers LLP.
  23.2*
  Consent of Brian A. Berube, Vice President and General Counsel (included in Exhibit 5.1).
  24*
  Power of Attorney (included on the signature page of this registration statement).
  *
  Filed herewith