Section 17-110. Sale and exchange of lymph and antitoxin

a. The department
  may authorize the sale at reasonable rates to be fixed by it, of surplus
  vaccine lymph,  virus,  diphtheria  antitoxin  and  other  vaccines  and
  antitoxins,  when  the amount collected shall exceed the amount required
  by it in the proper performance of its duties. The avails of such  sales
  shall  be  credited by the department to the general fund of the city of
  New York and  included  in  its  semi-monthly  transmission  of  revenue
  collections to the commissioner of finance of the city of New York.
    b.  The  bureau  of  laboratories of the department may also exchange,
  upon authority and approval of the commissioner, and  upon  the  written
  approval  of  the  mayor, a portion of its laboratory products for other
  and different laboratory products, manufactured by the  laboratories  of
  the United States government and of other cities and laboratories, which
  the department may need for the prevention of the spread of disease.