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                                                              December 22, 1999


C3D Inc.
230 Park Avenue, Suite 453
New York, NY 10169

Attn: Eugene Levich
      President and CEO

Re: Amendment No. 1 to Placement Agency Agreement
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Dear Dr. Levich:

         The parties hereto, C3D Inc., a Florida corporation (the "Company") and
Sands Brothers & Co., Ltd., a Delaware corporation ("Sands Brothers") have
entered into that certain placement agency agreement (hereinafter the "Agency
Agreement") dated as of December 1, 1999.

         In connection therewith, the parties hereto agree that the Agency
Agreement is hereby amended as follows:

         1. Paragraph 2(k) of the Agency Agreement is hereby deleted in its
entirety and in its place and stead the following is inserted:

               "(k) Agreements. Except as set forth in Schedule
               2(k) hereto, the Company is not a party to any
               written or oral contract, agreement, arrangement
               or understanding which is material to the business
               of the Company or which is material to, and which
               a prudent investor would need to review in order
               to make an informed investment decision with
               respect to the purchase of the Securities offered
               pursuant to the Offering Documents. The Company
               has performed in all material respects all
               obligations to have been performed on such
               contracts through the date hereof, and the Company
               is not in default in any material respect under
               any such contract. Each material contract of the
               Company is valid and binding on the Company and
               the Company has not received notice that any such
               contract is not binding on any party thereto."
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C3D Inc.
December 22, 1999
Page 2

         2. Paragraph 2(r) of the Agency Agreement is hereby deleted in its
entirety and in its place and stead the following is inserted:

               "(r) Brokers. The Company has not, or any of its
               respective officers, directors, employees or
               shareholders, employed any broker or finder in
               connection with the transactions contemplated by
               this Agreement, other than Sands Brothers, except
               as previously disclosed to Sands Brothers and for
               whose fees the Company shall be solely
               responsible."

         3. Paragraph 5(g) of the Agency Agreement is hereby deleted in its
entirety and in its place and stead the following is inserted:

               "(g) Ratification and Confirmation of Letter
               Agreement. The Company hereby confirms and
               ratifies the Letter Agreement including, without
               limitation, (i) the retention of Sands Brothers as
               its exclusive investment banker and financial
               consultant for a period of three (3) years
               following the completion of the Financing, at an
               annual fee of Forty Eight Thousand ($48,000)
               Dollars (exclusive of any accountable
               out-of-pocket expenses), payable quarterly in
               advance in installments of Twelve Thousand
               ($12,000) Dollars, with the first payment to be
               made upon the sale of the Minimum Amount by
               deduction of the proceeds therefrom, pursuant to
               Section 7 thereof, provided, however, that in the
               event that $25 million of Securities have not been
               sold within one year after the Commencement Date,
               Sands Brothers' status as investment banker and
               financial consultant to the Company, thereunder
               and hereunder, shall cease to be exclusive (ii)
               subject to $25 million of Securities having been
               sold, the granting of the right of first refusal
               to Sands Brothers pursuant to Section 8 thereof as
               described in Exhibit E hereto, (iii) subject to
               $25 million of Securities having been sold, the
               granting of the right to designate a board member
               or observer to the board of directors of the
               Company pursuant to Section 9 thereof after the
               Closing Date, and (iv) the expense reimbursement
               and indemnification provisions thereof. Such
               ratification and confirmation shall survive any
               termination of the Offering."

         4. Except as set forth herein, the Agency Agreement shall remain in
full force and effect.
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C3D Inc.
December 22, 1999
Page 3

         IN WITNESS WHEREOF, the Company and Sands Brothers have caused this
Agreement to be executed by its duly authorized representative.

C3D INC.                                       SANDS BROTHERS & CO., LTD.


By: /s/ Eugene Levich                          By: /s/ Mark G. Hollo
   ---------------------------------              -----------------------------
   Name:  Eugene Levich                               Name:  Mark G. Hollo
   Title: President and CEO                           Title: Managing Director

Date: December 22, 1999                        Date: December 22, 1999
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