The Globulins of the Jack Bean, Canavalia Ensiformis

While working with the urease of the jack bean, the author has had occasion to study the nature of the proteins that are present. The proteins of the jack bean have been investigated by Jones and Johns,’ who claim to have isolated an albumin and two globulins. The precipitate obtained by half saturation with ammonium sulfate, present in small amount and having the greater sulfur content, they called concanavalin. The precipitate by complete saturation with ammonium sulfat.e, present in large amount and containing less sulfur, was named canavalin. The only reason Jones and Johns had for considering the jack bean to contain two globulins was the different sulfur content of these two fractions. Jones and Johns dialyzed jack bean extracts and found that spheroids were formed. The author has found not two but three globulins present in the jack bean. Two of these globulins crystallize readily upon dialysis, while the third appears to be incapable of crystallizing. These three globulins can readily be separated by virtue of then markedly different solubilities. The greater part of the precipitate by dialysis consists of spheroids and represents the uncrystallizable globulin; this is readily soluble in 1 per cent sodium chloride solution. It also dissolves in distilled water when the acid combined with it has been neutralized. The author believes that the name canavalin, applied by