90 PROTEIN POISONS 



Colon Poison 



The yield from the colon poison was exceedingly small, due to the fact 

 that at one stage of the process part of the solution was lost. 



Albumin Poison. 



Temperature Amount of Weight of 



Fraction. of bath. distillate. crude crystals. 



1 40 to 60 5 c.c. 0.2638 gram 



2 60 to 80 3 c.c. 0.3338 gram 



3 80 to 100 8 c.c. 4.0000 grams 



4 100 to 130 10 c.c. 6.0000 grams 



5 130 to 160 7 c.c. 7.0000 grams 



After repeated recrystallizations these crude products 

 were obtained in a state of chemical purity. From the 

 tuberculosis poison, fractions 1 and 2 yielded needle-shaped 

 crystals, soluble in water and alcohol, sweet to the taste, 

 and containing 15.773 per cent, of nitrogen, the average 

 of four determinations by the Kjeldahl method. Alanin, 

 C 3 H 7 NO 2 , has all these properties and contains 15.73 per 

 cent, of nitrogen, thus identifying the crystals as alanin. 

 Fisher, Fraenkel, and others do not give a melting point for 

 d-alanin, saying that it is not sharp, due to the presence of 

 a mixture of the optically active and racemic forms. The 

 melting-point of the crystals from the tubercle poison 

 varied from 268 to 280 corrected, showing no constant 

 temperature. In fractions 3 and 4 the crystals were beau- 

 tiful, shiny, satiny plates, sweet to the taste, soluble in 

 water, but almost insoluble in alcohol. These sublimed 

 readily, melted with decomposition, and contained 11.976 

 per cent, of nitrogen (average of eight determinations). 

 These properties and the nitrogen correspond with valin, 

 a-aminoisovalerianic acid, C5HnNO2, which contains 11.965 

 per cent, nitrogen. Frankel gives the melting-point of 



