I. THE MAKING OF THE MOLD
THE MAKING of naturalistic, seamless, prosthetic hands of plastic materials such as rubber latex and Plastisol has presented numerous difficulties. We have not been able to find any evidence of plastic materials such as gelatin being employed for prosthetic hand making. When it became common practice to compound rubber latex in this country, one of us (C. D. C.) experimented with this material for making prosthetic hands and facial features. Molds of plaster, agar, rubber, metal and wax were.used. The agar mold first seemed to be the most logical, because by the use of this material a comparatively seamless cast could be produced. However, the mere fact that a new agar mold, or negative, had to be made for each positive, or cast, caused this material eventually to be discarded. Early experiments about eighteen years prior to the writing of this paper with gypsum