A transfers Rs. 500 to his niece C, if she will desert her husband. The transfer is

This is illustration (d) to section 25 of the Transfer of Property Act, 1882, under which an interest dependent upon a condition fails if the condition is forbidden by law, fraudulent, or regarded by the court as immoral or opposed to public policy. A condition that the niece desert her husband is immoral and opposed to public policy, so the transfer is "Void", not merely "Voidable". The same policy appears in section 23 of the Indian Contract Act, 1872 for agreements, but this transfer is governed by section 25 of the Transfer of Property Act.