461. Selection patents.

Since prima facie disclosure of a class involves disclosure of each of its members1, a claim in the specification of a selection patent2 to such a selected group prima facie lacks novelty3, but such a claim may have not only novelty but also inventive subject matter if the members of the selected group have some special property not possessed by the class as a whole4. This property must be stated in the specification5 as being a property in some sense peculiar to the selected class6.

A mere statement of the properties which a substance must possess in order to serve