[Letterhead of]
                                    CRAVATH, SWAINE & MOORE











                                                                  August 2, 1996


                                 Agreement and Plan of Merger
                                 Dated as of August 2, 1996,
                             Among Bristol-Myers Squibb Company,
                           OTN Acquisition Sub Inc. and Axion Inc.


Dear Sirs:

               We have acted as counsel  for  Bristol-Myers  Squibb  Company,  a
Delaware   corporation  ("BMS"),  and  OTN  Acquisition  Sub  Inc.,  a  Delaware
corporation  and wholly owned  subsidiary of BMS ("BMS Sub"), in connection with
the  proposed  merger  (the  "Merger")  of BMS Sub with and into Axion  Inc.,  a
Delaware  corporation  (the  "Company"),  pursuant to an  Agreement  and Plan of
Merger dated as of August 2, 1996 (the "Merger  Agreement"),  among BMS, BMS Sub
and the Company,  under which each issued and outstanding  share of common stock
of the Company  (other than shares owned directly by BMS or the Company) will be
exchanged solely for common stock of BMS.

               In that  connection  you have  requested  our  opinion  regarding
certain Federal income tax consequences of the Merger. In providing our opinion,
we have  examined  the Merger  Agreement,  the Form S-4  prepared by BMS and the
Company (the "Form S-4") and such other  documents and  corporate  records as we
have deemed  necessary or appropriate for purposes of our opinion.  In addition,
we have assumed that (i) the Merger will be consummated  in accordance  with the
provisions  of the  Merger  Agreement  and the Form  S-4,  (ii)  the  statements
concerning the Merger and the  Contributions and the Distribution (as defined in
the  Merger  Agreement)  and  related  transactions  set forth in the  documents



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referred to in Section 3.01 of the Merger  Agreement  are accurate and complete,
(iii) the representations made to us by BMS and the Company in letters dated the
date hereof and attached as Exhibits A and B hereto and the  representations  of
certain  stockholders  of the Company in their  respective  letters to us in the
form of  Exhibit C hereto  and  delivered  to us for  purposes  of this  opinion
(collectively,  the "Representation Letters") are accurate and complete and will
remain accurate and complete at all times up to and including the Effective Time
(as  defined  in the Merger  Agreement),  (iv) any  representations  made in the
Representation  Letters  therein  "to the  best of  knowledge  of" or  similarly
qualified are correct  without such  qualification  and (v) as to all matters in
which a person or entity has  represented in any of the  Representation  Letters
that such person or entity  either is not a party to,  does not have,  or is not
aware of any plan,  intention,  understanding  or  agreement  to take an action,
there is in fact no such plan,  intention,  understanding or agreement as of the
date  such  representation  is made  and at all  times up to and  including  the
Effective  Time of the Merger and such action will not be taken.  If any of such
assumptions are untrue,  for any reason,  our opinions as expressed below may be
adversely affected and may not be relied upon.

               Based upon the foregoing, for Federal income tax purposes, we are
of the opinion that:

               (i) the  Merger  will  constitute  a  reorganization  within  the
        meaning of Section  368(a)(1) of the Internal  Revenue Code of 1986,  as
        amended  (the  "Code"),  and BMS, BMS Sub and the Company will each be a
        party to such reorganization within the meaning of Section 368(b) of the
        Code; and

             (ii)  no gain or loss  will be  recognized  by BMS,  BMS Sub or the
        Company in the Merger.




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               This opinion is being provided  solely for the benefit of BMS and
BMS Sub. No other person or party shall be entitled to rely on this opinion.


                                             Very truly yours,




Bristol-Myers Squibb Company