692. Merger prevented by the contract.

692.     Merger prevented by the contract.

Merger may be prevented by an express or implied intention to the contrary1. Thus an assignment made by way of further security cannot prejudice the continuance of any existing security for the same debt2, and a mortgage is not merged by the taking of a new mortgage on the same property to cover the original debt and further advances3. A covenant to pay interest can be so expressed as not to merge in a judgment4.