154 MacDOUGAL and SPOEHR— COMPONENTS AND 



4. Glycocoll and glycocoll ester increase the swelling of agar. 

 Glycocoll lessons swelling of gelatine, while glycocoll ester, glycocoll 

 ester hydrochloride and glycocoll hydrochloride increase it beyond 

 that shown in distilled water. 



5. The hydroxides of the strong metallic bases limit the hydra- 

 tion of agar according to their position in the electromotive series, 

 the least swelling taking place under the action of the strongest base 

 at concentrations of o.oi A'^ with the apparent exception of rubidium. 

 Beginning with the strongest the series runs K (Rb) Na Li. 



6. The various effects of barium, calcium and strontium are not 

 so clearly determined and the quantitative relations of these metals 

 are not known definitely. Hydration values of agar at o.oi A^ were 

 Sr(OH), = 8i5, Ca(OH), = 86o, Ba(0H), = 900. 



7. Hydration of agar in calcium hydroxide exceeds that in water 

 at o.oooi N of the hydroxide and this effect is also produced at 

 o.ooooi A^. Increase of hydration beyond that of water by dilute 

 solutions of hydroxides of calcium, potassium, rubidium, potassium 

 sodium and lithium is an effect we have hitherto ascribed to amino- 

 compounds only. Excess values for aniline and ammonium hy- 

 droxide are given. 



8. The incorporation of bases in agar lessens its hydration ca- 

 pacity in any concentration yet tested, and this is also true of biocol- 

 loids of which carbohydrates constitute more than half. In mix- 

 tures containing more gelatine hydration capacity in acids and in 

 hydroxides may be increased by included bases. The inclusion of 

 a metallic base and its presentation in a hydrating solution would 

 give different results in a colloidal or plasmatic body such as 3. 

 nucleus or chromosome. 



9. The data in this article were secured chiefly by the swelling 

 of trios of sections with a total volume of 4 to 8 cu. mm. under the 

 auxograph in dishes into which 25 to 30 cc. of solution was placed 

 and renewed at intervals of 12 and 24 hours. Such renewals were 

 attended by accelerations in the rate and increases in the total swell- 

 ing. Agar and biocolloids of agar and gelatine showed this action 

 in a marked manner. Sections of equal parts of these two com- 

 ponents exhibited reactions in which the exaggerated swelling re- 

 sulting from renewals were partly retracted very slowly on the third 



