Transfer of Property Act, 1882
81. Marshalling securities
If the owner of two or more properties mortgages them to one
person and then mortgages one or more of the properties to another person, the
subsequent mortgage is, in the absence of a contract to the contrary, entitled
to have the prior mortgage-debt satisfied out of the property or properties not
mortgaged to him, so far as the same will extend, but not so as to prejudice
the rights of the prior mortgagee or of any other person who has for
consideration acquired an interest in any of the properties.