82 PROTEIN POISONS 



Bath temperature. Yield. 



Fraction I 40 to 60 16.5 grams 



Fraction II 60 to 80 8.5 grams 



Fraction III 80 to 100 22.5 grams 



Fraction IV 100 to 130 20.0 grams 



Fraction V 130 to 160 16.5 grams 



The dark red residue left in the distillation flask was 

 dissolved in hot alcohol, decolorized with animal charcoal, 

 filtered, and from the filtrate 0.5 gram of leucinimid was 

 obtained. 



Fraction I. This was saponified by boiling with five 

 times its weight of water for five hours with a reflux con- 

 denser. On concentration two crops of crystals were 

 obtained. The first was dissolved in the smallest possible 

 amount of hot water, then treated with an equal volume 

 of alcohol, and left in the ice-box for twenty-four hours. 

 The white crystalline mass, tasting sweet and closely 

 resembling alanin, weighed 1.75 grams. 



The second crop was obtained by evaporation to dryness, 

 and weighed 1 gram. It was dissolved in 3 c.c. of hot 

 water; this was poured into an equal volume of hot absolute 

 alcohol, and set in the ice-box for twenty-four hours. White 

 needle-like crystals, sweet to the taste and arranged in 

 bundles, formed. These were recrystallized, washed with 

 absolute alcohol, dried, and weighed. The yield was 0.5 

 gram. These crystals sublimed on heating and were prob- 

 ably valin, although it will be seen that neither of these 

 bodies has been positively identified. 



Fraction II. This on being saponified by boiling with 

 five times its weight of water for five hours under a reflux 

 condenser and concentrated, yielded a crystalline mass 

 that contained no prolin, since no part of it was soluble in 

 hot absolute alcohol. The crystalline mass. was dissolved 

 in 700 c.c. of water and boiled for an hour with an excess of 

 freshly prepared copper oxide. On concentration of the 

 blue filtrate, a difficultly soluble salt was obtained. This 

 was crystallized and the percentage of copper in it found 

 to be 20.35, thus identifying it as the double salt of copper 

 with leucin and valin. 



