By sec. 118 of Act No. 1128 it is provided that "If any person knowingly puts into any post office in Victoria any letter, packet, parcel or newspaper, bearing any indecent, obscene, profane or libellous address, signature, marks, words, or designs, or containing any indecent or obscene print, photograph, lithograph, writing, engraving, book, or card, or other indecent or obscene article, he shall be liable to a penalty not less than five nor exceeding fifty pounds."