a pledge in law, is either vicium or mortuum.

Vadium Vicium, or Living Pledge, is when a man borrows a sum (suppose 200l.) of another; and grants him an estate, as of 20l. per annum, to hold till the rents and profits shall repay the sum so borrowed. This is an estate conditioned to be void as soon as such sum is raised. And in this case the land or pledge is said to be living: it subsists, and survives the debts; and immediately on the discharge of that, reverts to the borrower.