EXHIBIT 10.3

                            STOCK PURCHASE AGREEMENT

         This Stock  Purchase  Agreement,  dated as of  December  15,  1998 (the
"Agreement"),  is by and between PARACELSIAN,  INC., a Delaware corporation with
its  principal  offices  in the State of New York (the  "Company"),  and JOHN A.
WILLIAMS, a resident of the State of North Carolina (the "Investor").

         WHEREAS,  the Company desires to sell, and the Investor desires to buy,
a certain  number of shares of common stock of the Company on certain  terms and
conditions (the "Shares").

         NOW THEREFORE, in consideration of the foregoing,  the mutual covenants
hereinafter contained,  and other good and valuable  consideration,  the parties
hereto agree as follows:

         1.       CERTAIN DEFINITIONS.  As used in this Agreement, the following
terms shall have the following respective meanings:

                  "Commission"   shall   mean  the   Securities   and   Exchange
Commission, or any other federal agency at the time administering the Securities
Act.

                  "Common Stock" shall mean the common stock of the Company,  as
constituted as of the date of this Agreement.

                  "Restricted Stock" shall mean the "Shares".

                  "Securities  Act" shall mean the  Securities  Act of 1933,  as
amended,  or any similar federal  statute,  and the rules and regulations of the
Commission thereunder, all as the same shall be in effect at the time.

         2.       THE SALE.  (a) Upon the terms and subject to the conditions of
this  Agreement,  the Company agrees to sell,  assign,  transfer and deliver the
Shares to the  Investor,  and the  Investor  agrees to accept and  purchase  the
Shares from the Company.  

        (b)       CONSIDERATION.  Upon the terms and  subject to the  conditions
contained  in this  Agreement,  the Investor  hereby  delivers to the Company in
immediately  available  United States funds the aggregate amount of $250,000 for
666,666 Shares (the "Purchase Price").

        (c)       CERTIFICATES. As soon as practicable, the Company will deliver
to the Investor  the stock  certificates  representing  the Shares and any other
documents  that are  necessary  to  transfer to the  Investor  good title to the
Shares.

         3.       REPRESENTATIONS   AND  WARRANTIES  OF  COMPANY.   The  Company
                  represents and warrants as follows:  
                  (a) EFFECT OF TRANSFER  OF SHARES.  Upon  consummation  of the
transactions  contemplated by this Agreement, the Investor will acquire from the
Company the Shares to be transferred by the Company to Investor,  free and clear
of all  Restrictions,  other than such  Restrictions  on  transfer of the Shares
arising  under  federal or state  securities  laws,  and will own such shares of
record.
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                  (b)  PERFORMANCE.  The execution,  delivery and performance of
this  Agreement  by the  Company  have been  duly  authorized  by all  requisite
corporate  action and will not violate any  provision  of law,  any order of any
court or other agency of government,  the certificate of incorporation or bylaws
of the Company or any provision of any indenture,  agreement or other instrument
to which it or any or its properties or assets is bound,  conflict with,  result
in a  breach  of or  constitute  (with  due  notice  or lapse of time or both) a
default under any such indenture, agreement or other instrument or result in the
creation  or  imposition  of any  lien,  charge  or  encumbrance  of any  nature
whatsoever upon any of the properties or assets of the Company.

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                  (c)  REGISTRATION.  The Company intends to file a registration
statement  with the Commission to register  securities  under the Securities Act
for the account of certain  security holders within ninety (90) days of the date
of this Agreement. The Company agrees, subject to compliance with all applicable
laws and regulations,  to use its best efforts to (i) effect such  registration;
and (ii) include the Shares acquired by the Investor  pursuant to this Agreement
in such registration statement.

         All of the above  representations  and  warranties  shall  survive  the
making of this Agreement.

         4.  REPRESENTATIONS AND WARRANTIES OF INVESTOR.  As of the Closing, the
Investor represents and warrants as follows:

                  (a)  ACCREDITED   INVESTOR.   The  Investor  qualifies  as  an
accredited  investor  within  the  meaning  of the  Securities  Act,  and is not
acquiring the Shares for the account or for the benefit of any other person.

                  (b)  ACQUISITION  OF STOCK FOR  INVESTMENT.  The  Investor  is
acquiring the Shares for investment  and not with a view toward,  or for sale in
connection with, any  distribution  thereof,  nor with any present  intention of
distributing or selling such Shares. The Investor  acknowledges that such Shares
have not been  registered  under the Securities  Act, and such Shares may not be
sold, transferred, offered for sale, pledged, hypothecated or otherwise disposed
of without registration under the Securities Act and other applicable securities
laws, except pursuant to an available exemption from such registration under the
Securities Act and such laws.

                  (c) FINANCING.  Investor has available to it funds  sufficient
to complete the transactions contemplated by this Agreement.

         All of the above  representations  and  warranties  shall  survive  the
making of this Agreement

         5.       RESTRICTIVE LEGEND. Each certificate  representing  Restricted
Stock shall be stamped or otherwise  imprinted with a legend indicating that the
Shares  have  not  been  registered  under  the  Securities  Act  and may not be
transferred without an effective  registration  statement or the availability of
an exemption from the registration provisions of the Securities Act.

         6.       MISCELLANEOUS.   (a)  BINDING   EFFECT.   All   covenants  and
agreements  contained  in this  Agreement  by or on behalf of any of the parties
hereto  shall bind and inure to the  benefit of the  respective  successors  and
assigns of the parties hereto (including without  limitation  transferees of any
Restricted Stock), whether so expressed or not.

                  (b)  GOVERNING  LAW. This  Agreement  shall be governed by and
construed in accordance  with the laws of the State of North  Carolina,  without
giving effect to the principles of the conflicts of laws thereof.

                  (c)  ENTIRE  AGREEMENT.  This  Agreement  contains  the entire
agreement of the parties with respect to the  transactions  described herein and
supersedes any and all other oral or written  agreement(s)  heretofore made, and
there are no representations or inducements by or to, or and agreements between,
any of the parties hereto other than those contained herein in writing.

                  (d)  COUNTERPARTS.  This  Agreement  may be executed in two or
more counterparts,  each of which shall be deemed an original,  but all of which
together shall constitute one and the same instrument.

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         IN WITNESS WHEREOF, this Agreement has been executed as of the date and
year first above written.
                                 INVESTOR

                                 /s/ John A. Williams  
                                 -----------------------------------------------
                                     John A. Williams

                                  PARACELSIAN, INC.

                                  By: /s/ Bernard M. Landes     
                                     -------------------------------------------
                                          Dr. Bernard M. Landes
                                          President and Chief Executive Officer