25. Whenever a notice or copy of an order may be served under the provisions of this Act, such service shall be made in the manner provided for the service of a summons in the Code or Criminal Procedure, 1898, provided that if service is to be made under the provisions of section 71 of that Code, and it is not known where the person on whom such notice or the copy of such order is to be served ordinarily resides, the serving officer shall affix one of the duplicates of such notice or such copy of such order to some conspicuous part of the premises to which such notice or order relates.