Effect of Certain Organic Acids and Amino Compounds. 57 



a swelling less than that in distilled water, a result that suggests a 

 rapid solution or dispersion from the surfaces of the sections and alter- 

 ations of viscosity in the mass. 



TABLE 45. Hydration of agar, gelatine, agar-gelatine, and agar-oat protein in organic acids 

 and their amino-compounds at 16 to 17 C. Expansion in percentages of dried thickness. 



Mixtures of agar (8 parts) and gelatine (2 parts) were now tested, 

 and the hydration in succinic acid at 0.00008 M was but 1,030 per 

 cent, as compared with 1,684 per cent in water, while acetic acid was 

 slightly higher, 1,167 per cent. A similar statement would hold for 

 the action of these acids on agar and for agar-protein, the hydration 

 in water alone being reached more nearly than in the agar-gelatine 

 sections. 



When we now turn to amino-succinic or aspartic acid and amino- 

 acetic acid or glycocoll, some new relations are uncovered. The 

 aspartic acid appeared to exercise a notable influence on the hydration 

 of agar. The limit of its solubility appeared to be about 0.05 M 

 at 15 to 20 C. When more than this was added to the water 



