New YorK AGRICULTURAL EXPERIMENT STATION. 209 
The diagrammatic curves of Fig. 16 signify that,— 
(1) When an insoluble base forming an insoluble hydrolyzible 
salt is treated with acid of the equilibrium concentration (curve 3), 
as, for example, 13.8 mgs. per cc. in the case of picric acid and 
diphenylamine, none of the acid is combined, so that its concen- 
tration remains constant. 
Concentration A ar ae 
Duration of Reaction—> 
Fic. 17——Typical curves for adsorption. 
(2) Likewise, when the initial concentration is less than that re- 
quired for equilibrium, none is combined (curve 4). 
(3) When the initial concentration is greater than that required 
for equilibrium (curves 1 and 2), acid is combined until the con- 
centration of free acid is reduced to the equilibrium value, which 
is the same, whatever the initial concentration of the acid, 
