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                                                                      EXHIBIT 23
 
                       CONSENT OF INDEPENDENT ACCOUNTANTS
 
We consent to the incorporation by reference in the registration statements of
Cabot Corporation on Form S-3 (File Nos. 33-18883, 33-48686) and on Form S-8
(File Nos. 33-28699, 33-52940, 33-53659, 333-03683, 333-06629, 333-19103 and
333-19099) of our report dated October 23, 1997, except for the information in
Note B, for which the date is December 18, 1997, on our audits of the
consolidated financial statements of Cabot Corporation as of September 30, 1997
and 1996, and for each of the three fiscal years in the period ended September
30, 1997, which report is included in this Annual Report on Form 10-K.
 
                                          Coopers & Lybrand L.L.P.
Boston, Massachusetts
December 19, 1997