PROTEINS 



line obtained from proteins is levo-rotatory and is the only protein de- 

 composition product which is readily soluble in alcohol. It is also one of 

 the few heterocyclic compounds obtained from proteins. Proline has 

 been found among the decomposition products of all proteins except the 



FlG. 32. LEVO-a-PROLINE. 



protamines. The maximum yield reported is 13.73 P er cen t obtained 

 by Osborne and Clapp from the hydrolysis of hordein. Fischer and 

 Boehner 1 have obtained 7.7 per cent from the hydrolysis of gelatin. 



FIG. 33. COPPER SALT OF PROLINE. 



Reproduced from a micro-photograph made by Prof. E. T. Reichert, of the University of 



Pennsylvania. 



The crystalline form of hw-a-proline is shown in Fig. 32 and the 

 copper salt of proline is represented by a micro-photograph in Fig. 33. 

 The crystals of the copper salt have a deep blue color, but when they 

 Fischer and Boehner: Zeit. phys. chem., 65, 118, 1910. 



