170. Accretions and substitutions.

The mortgagee is entitled to accretions to the mortgaged property or property received in substitution for it by the mortgagor1. Similarly, additions made by a second mortgagee enure to the benefit of the first mortgagee2. If the mortgaged property is disposed of in a manner which destroys the mortgagee's estate3, a security interest automatically arises in the proceeds of sale in favour of the mortgagee4. In the case of renewable leaseholds, if either the mortgagor or mortgagee is able to obtain a renewal of the lease, the renewed lease is treated as engrafted upon the old and as forming