86 COLLOID CHEMISTRY OF THE PROTEINS 



behaviour is desamino-glutin, which is easily soluble in water 

 (L. Blasel and J. Matula).* With the removal of amino-groups 

 glutin loses completely its characteristic property of gelatinisa- 

 tion. It gives a clear solution of distinctly acid character, as 

 might be expected. It reddens litmus and in 075 per cent, 

 solution gives a hydrion concentration of 1-79 X io~ 5 N. 



It is remarkable to note, however, that desamino-glutin still 

 shows a considerable power of combining with acids. 



Table 36. 

 0*75 per cent. Desamino-glutin -f HC1. 



Whereas we can estimate the maximum combining capacity 

 of a 0-75 per cent, desamino-glutin solution as 9 x io~ 3 N HC1 



per litre, a glutin 



solution of equal con- 



centration takes up 

 on the average 

 1-15 X io- 2 N HC1. 

 Thus, after removal of 

 amino - groups, about 

 78 per cent, of the 

 power of combining 

 with acids remains. 

 The chlorion of the 

 combined acid is at 



ovz 



OV1 



H 



O'Oi 00 OV3 

 FIG. 20. Desamino-glutin and hydrochloric acid. 



first completely dissociated (see Fig. 20) up to an acid concen- 

 tration of 0-015 N HC1, and then in excess of acid its ionisation 

 is suppressed. Hence desamino-glutin also forms a salt ionised 

 like a typical chloride, and, further, a consideration of the 

 * Biochem. Zeitsch., 1914, 58, 417. 



