650. Statutory receipt given by the mortgagee.

A receipt given by the mortgagee or his successor in title for all principal, interest and costs is usually in the form of a 'statutory receipt'. A statutory receipt must be indorsed on, written1 at the foot of, or annexed to the mortgage2, and must be for all the money thereby secured3. Where the mortgage consists of a mortgage and further charge, or of more than one deed, it is sufficient if the receipt refers either to all the deeds or to the aggregate amount of the mortgage money4 secured by them and for the time being owing, and