e. One may ask,
why does the rule not work both ways? There is a much stronger
probability of making a mistake in the second case than in the other.
One of the facts of great importance in such a dispute is the amount
of the consideration or money paid. Suppose a piece of land was worth
$1000 and the deed mentioned only $100, unless there was some other
explanation, there would be a strong probability that the parties
intended only a mortgage which for some reason or other was not
completed.

Again, it is a rule of law that an agreement which is in fact a
mortgage cannot be changed in character by any other agreement made at
the time between the parties relating to the repayment of the money
and the return of the property. The law presumes that the entire
transaction was embodied in the agreement. "Once a mortgage always a
mortgage." Of course this rule does not prevent the parties from
making any later arrangement they please about the property.

A mortgage may be made with a power of sale whereby, should the debt
be not paid at the time fixed, a valid title may be acquired by a
purchase from the mortgagee. The mortgagee thus becomes a kind of
trustee or agent for the debtor. This is a great responsibility to
repose in the mortgagee, and he must perform the trust in good faith
in every respect. He must proceed in a way that will best serve the
interest of the mortgagor, and strictly observe the terms stated in
the mortgage, otherwise the sale will not be valid and the mortgagor
can recover his property. If there is a surplus after satisfying the
mortgage debt it must be paid to the mortgagor, or, if he is dead, to
his heir. Such deeds of trust are made by large corporations to secure
loans, and may be made to secure future advances as well as present
ones.

If the property is sold to satisfy the mortgage debt, the mortgagee
cannot purchase it, unless authorized by statute, or by the terms of
the mortgage; but if it is sold by an officer of the law, the
mortgagee is as free to purchase it as any other individual. This
rule, though, is denied by some courts, which hold he cannot because
the officer is acting as the mortgagee's agent.

A vendor or seller of property, may have for the money he is to
receive a lien, which is nearly the same thing as a mortgage. A
subsequent purchaser would be affected by this lien, however innocent
he might be of its existence. But if the purchaser should mortgage the
property to a th