Exhibit 10.1

          Escrow Agreement, effective as of May 31, 1999 by and among:


                  The  holders of  Hemispherx  Biopharma,  Inc.  warrants as set
                  forth on Schedule A attached hereto ("Warrantholders");

                  HEMISPHERX  BIOPHARMA,   INC.,  a  Delaware  corporation  with
                  offices   located   at  1617  JFK   Boulevard,   Philadelphia,
                  Pennsylvania 19103 ("Company"); and

                  SILVERMAN,  COLLURA &  CHERNIS,  P.C.  as Escrow  Agent,  with
                  offices  located at 381 Park Avenue South,  New York, NY 10016
                  ("Escrow Agent")

         WHEREAS,  the  Company  has  agreed  to file a  registration  statement
("Registration  Statement") with the Securities and Exchange  Commission ("SEC")
to register the warrants  ("Warrants") and the shares of common stock underlying
the Warrants  (collectively,  the "Shares") under the Securities Act of 1933, as
amended ("Act") which are owned by the Warrantholders  identified on Schedule A;
and

         WHEREAS, the Warrantholders have agreed to allow the Company to arrange
for the sale of the Shares through an agent or agents,  as yet to be determined,
pursuant to the terms and conditions of this Agreement;  and (ii) to release the
Company  from any and all claims  relating to or arising  from any  registration
rights contained in the Warrants; and

         WHEREAS,  the Company has agreed to use its best efforts to arrange the
sale of the Warrants from the Warrantholders,  through an agent or agents as yet
to be  determined,  on a  best-efforts  basis,  during the twelve  month  period
commencing  on the date the SEC declares the  Company's  Registration  Statement
effective, pursuant to the terms and conditions contained herein.

         NOW, THEREFORE,  in consideration of the covenants set forth herein, it
is mutually agreed as follows:

1.  Terms:

         1.1   The Company  agrees to purchase,  or designate an agent or agents
("Placement Agent") to purchase,  on a "best efforts" basis within twelve months
of the date the SEC declares the Registration  Statement  effective  ("Effective
Date"),  the Warrants  from the  Warrantholders.  There is no  assurance  that a
Placement Agent will be designated or that the Company or a Placement Agent will
purchase all or a portion of the Warrants from the Warrantholders.


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         1.2   Each Warrantholder  shall set a purchase price ("Purchase Price")
at which the  Warrantholder  will sell his or her  Warrants  to the  Company  or
Placement Agent by completing the Purchase Price Election Form,  attached hereto
as Exhibit B. The  Purchase  Price shall be  discounted  10%,  representing  the
Placement  Agent's  commission  on the sale.  The  Company  will not receive any
commissions on sales made by the Company.  The Warrantholder's net proceeds will
equal the Purchase Price, less the 10% commission.

         1.3   Upon  execution  of  this  Agreement,  the  Warrantholders  shall
deliver to the  Escrow  Agent a copy of this  Agreement  and the  Warrants.  The
Escrow  Agent shall hold the  Warrants in escrow until the earlier of (i) twelve
months from the Effective  Date; or (ii) such time that the Company or Placement
Agent  notifies the Escrow  Agent in writing  ("Purchase  Notice")  that it will
purchase a portion of, or all, the Warrants.

         1.4   Upon receipt from the Placement  Agent of the Purchase Notice and
the Purchase  Price  relating to Warrants for which such Purchase Price has been
set by a  Warrantholder,  the  Escrow  Agent  shall (i) pay to the  Company  the
exercise price for the Warrants  purchased by such Placement Agent; (ii) release
the  appropriate  number  of  Warrants  to the  Company's  transfer  agent  with
instructions to issue the underlying  shares of common stock  applicable to such
Warrant to the such  Placement  Agent or its  designees;  and (iii) disburse the
escrow funds to the holders of the Warrants that were purchased.

         1.5   In the event the Purchase Price  delivered to the Escrow Agent by
the  Placement  Agent is not  sufficient  to purchase all the Warrants that have
such  Purchase  Price,  the  Warrants  shall  be  sold  in the  order  of  their
expiration.  Accordingly,  if the  event  described  in this  paragraph  occurs,
Warrants that expire first shall be sold first.  In the event there are Warrants
with the same expiration dates and the event described in this paragraph occurs,
the Warrants will be sold on a pro rata basis.

         1.6   Upon the  expiration  of the twelve month  period,  any remaining
Warrants will be returned to the respective registered owner thereof.

         1.7   The  Warrantholders  agree that,  upon the  effectiveness  of the
Registration  Statement under the Act registering the Shares,  which is referred
to in Section 2 herein,  any and all  obligations of the Company to register the
Shares  shall be deemed to have been  satisfied in full,  and,  except for those
obligations  specifically  set forth in  Section  2, the  Company  shall have no
further obligations with respect to the registration of the Shares.

2.       Registration Statement

         The Company  shall use its best  efforts to file with the SEC within 25
days of the execution of this  Agreement,  a Registration  Statement on Form S-3
under the  Securities  Act  registering  the Shares.  The Company  shall use its
reasonable  best  efforts to cause the  Registration  Statement  to be  declared
effective as soon as possible.  The Company shall timely take such action as may
be necessary to cause the  Registration  Statement to remain in effect until the
earlier  of (x)  the  date


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the last of the Shares have been sold by the Warrantholders,  or (y) twenty four
months  from  the  Effective   Date.   The  Company  may  require  each  of  the
Warrantholders  to  furnish  to the  Company  such  information  regarding  such
Warrantholder as the Company may from time to time reasonably request in writing
with respect to matters concerning the Company's  compliance with the Securities
Act and the Registration Statement filed thereunder. If a Warrantholder does not
furnish  such  requested  information  to the  Company  or  otherwise  fails  to
cooperate  with the  Company to the extent  necessary  to enable the  Company to
comply with its  obligations  under the Securities Act, the Company shall not be
obligated to register such Warrantholder's  Shares, but shall continue to remain
obligated to register the remainder of the Shares.  All expenses incident to the
Company's  performance of or compliance with this Article 2, including,  without
limitation,  all Commission and securities  exchange or National  Association of
Securities Dealers registration and filing fees, fees and expenses or compliance
with securities or blue sky laws, and printing  expenses,  shall be borne by the
Company.

3.       Miscellaneous Escrow Provisions.

         (a) The  Escrow  Agent  shall be  entitled  to rely  upon the truth and
accuracy of any notice received from a Placement Agent, the  Warrantholders,  or
the Company ("Parties") without any independent investigation or verification by
Escrow Agent.

         (b) The Escrow  Agent  undertakes  to perform  only such  duties as are
expressly set forth to be performed by it hereunder.

         (c) The  Escrow  Agent  shall not be liable to any Party in  connection
with its  performance  as Escrow  Agent  hereunder  other  than for its  willful
misconduct. The Escrow Agent shall not be liable to any Party for delays, timing
and/or  delivery  of  its  obligations  herein,   other  than  for  its  willful
misconduct. The Parties hereby jointly and severally indemnify and hold harmless
the  Escrow  Agent  from any and all  claims,  liabilities,  damages,  costs and
expenses (including, but not limited to, reasonable attorneys' fees) arising out
of or in  connection  with this  Agreement,  and any actions of Escrow  Agent in
connection therewith, other than Escrow Agent's willful misconduct.

         (d)  Upon the  distribution  of all of the  Warrants  under  the  terms
hereof,  the Escrow Agent shall be relieved of all liability,  responsibility or
obligation with respect to or arising out of this Agreement.

         (e) The Escrow Agent shall not be disqualified  from  representing  any
party,  its assigns or designees in any action between any of the Parties hereto
by the  reason of the fact that the  Escrow  Agent is acting as an escrow  agent
hereunder.

4.       Amendments;   Waiver.   This   agreement  may  be  amended,   modified,
superseded, canceled,


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renewed or extended and the terms and  covenants  hereof may be waived,  only by
written  instrument  executed by all parties hereto, or in the case of a waiver,
by the party waiving  compliance.  The failure of any party at any time or times
to require  performance  of any  provision  hereof shall in no manner affect the
right at a later  time to  enforce  the same.  No waiver by either  party of the
breach of any term or covenant  contained in this Agreement,  whether by conduct
or otherwise,  in any one or more instances,  shall be deemed to be or construed
as a further  continuing  waiver of any such breach or a waiver of the breach of
any other term or covenant contained in this Agreement.

5.       Governing  Law. This  Agreement  shall be governed by and construed and
enforced  according  to the local  laws of the State of New York  applicable  to
agreements made and to be performed entirely in such state.

6.       Assignment  This  Agreement.  Any  obligations  hereunder  may  not  be
assigned without the written consent of all parties hereto.

7.       Headings and Captions.  The section  Headings  herein are for reference
purposes only and shall not in any way affect the meaning or  interpretation  of
this Agreement.

8.       Notices.  Any notice or other  communication  required or  permitted by
this  Agreement must be in writing and shall be deemed to be properly given when
delivered in person to an officer of the other party,  or when  deposited with a
Federal  Express  employee  for  transportation  to the Escrow  Agents,  charges
prepaid provided that the  communication is addressed to the respective party at
the place  indicated on the first page of this Agreement or to such other person
or address designed by the parties to receive notice.

9.       Counterpart  Signatures.  The parties hereto may execute this Agreement
in any number of counterparts, each of which, when executed and delivered by all
the  parties,  shall  have the  force  and  effect  of any  original.  Facsimile
signatures  shall be  accepted  as  genuine  and  deemed  the  same as  original
signatures.

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         IN WITNESS WHEREOF,  the parties have executed this Agreement as of the
date first above written.


                                    WARRANTHOLDER

                                    --------------------------------------------
                                    Name:

                                    HEMISPHERX BIOPHARMA, INC.

                                    By:
                                       -----------------------------------------
                                             Dr. William A. Carter, President


                                    SILVERMAN, COLLURA & CHERNIS, P.C.

                                    --------------------------------------------
                                    Solely as Escrow Agent


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                                   SCHEDULE A


                                     Warrant
Name, Address and Phone #           Registration No.          No. of Warrants

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