A Blind Bargain(1922)

Robert dearly loved Angela, but alas! Too soon they have to part, for shortly he must leave her to fulfill a blind bargain with a mad genius of surgery!

Chaney plays two roles: mad scientist Arthur Lamb and Lamb's "experiment", known only as the Ape Man. This hideous creature was the result of Lamb's attempts to transplant animal glands into human beings. A lost film.