Section 204. Certification and approval of contracts and conveyances

No
  written contract providing for the payment of  two  hundred  dollars  or
  more,  entered  into  by  the  city  or  any  of its officers, boards or
  departments, shall become effective or be acted under until there  shall
  be  indorsed  thereon  by  the  corporation  counsel  or an assistant, a
  certificate to the effect that the city  officer,  board  or  department
  which  has  executed  the  same on behalf of the city, had authority and
  power to make such contract, and that such contract is  in  proper  form
  and  properly  executed; he shall approve all deeds, conveyances, leases
  and abstracts of title  affecting  property  acquired,  conveyed  to  or
  leased  by  the city; and he shall attend to all the law business of the
  city and discharge such other duties as may  be  prescribed  by  law  or
  ordinance of the common council.