Waste by mortgagor in possession.-
A mortgagor in possession of the mortgaged property
is not liable to the mortgagee for allowing
the property to deteriorate; but he must not
commit any act which is destructive or permanently
injurious thereto, if the security is insufficient
or will be rendered insufficient by such act.
Explanation: A security is
insufficient within the meaning of this section
unless the value of the mortgaged property exceeds
by one-third, or, if consisting of buildings,
exceeds by one-half, the amount for the time
being due on the mortgage.