135 
Let us first consider the equilibriums of the gelatinous hydroxide 
(a) with NaOH-solutions of various concentrations. In the more con- 
centrated solutions the particles swell very much and show a solu- 
ie 
bility that is considerably greater than that of the other forms of 
the hydroxide. Although in diluted solutions crystallization to product 
y arises very slowly, the rapidity of this transition is so slight, that 
after one or two months we still entirely measure the solubility of 
the gelatinous particles «. Most of the determinations performed with 
product « therefore form together the curve I; some that greatly 
deviate from this curve (see Nos. 10 and 11) have not been analysed 
till after a considerably longer time than the others. A considerable 
percentage of « had consequently been converted into y. Yet these 
points 10 and 11 are still situated far above curve III, which 
represents the solubility of y. This phenomenon requires our special 
attention, for if between the solid phases to which curves I and III 
refer, no continuous transition was possible, we then might expect 
to remain on curve I as long as the gelatinous phase was present 
and a subsequent sudden decline to curve III. The phenomenon 
observed here may have various causes: 
a. There is a continuous transition between the solid phases of 
curves I and Ill; between these curves we must imagine quite a 
