678. Nature of merger.

Merger may take the form of a merger of estates or of a merger of charges in the land1.

Where a charge on land and the ownership of the land become united in the same person, merger does not necessarily follow in equity2, and the equitable rule now prevails3.

In general, merger of charges, like the merger of estates, is in equity a question of intention and this intention may be actual or presumed4. The sole exception to this rule is that where the owner of land pays off a charge which he is personally liable to pay, he is not