Residuum

Remainder; residue.

1.

In patent law, what is left after a process of separation. There are as many different residuums of a substance as there are distinct products which may be taken away from it. Showing that all the matter that is in the residuum of the earlier of two patents is also in, and is obtained by separation from, the residuum of the patent of later date, does not make out an infringement on the former. It does not show that the patents are the same. If the rule were otherwise, a prior patent for the same use, of the common source, would cover both.

3.

The surplus of an estate after all debts and particular legacies are discharged. This goes to the residuary legatee; if none is named, then to the next of kin, under the intestate law. Anciently, the residuum was taken by the executor, unless otherwise directed. If a legacy is not legally disposed of, it falls into the residuum. But where a specific devise of realty is invalid, the realty descends to the heir at law.