ELISHA MITCHEIX SCIENTIFIC SOCIETY. 



59 



Table IV shows the rate of reversion for 4 weeks, absolute and 

 comparative, and the accompanying loss of moisture; 



TABLE IV. 



Soluble Phosphoric acid. 



S5 o 



. eS 



o_c 



(u 'So 



;:: o 



p. c. 

 34-55 

 34-05 

 30.61 



TABLE V— COMPARE TABLE II. 

 Behaviour of Insol. Phos. Acid. 



TABLE VI— COMPARE TABLE II. 

 Behaviour of Soluble and Reverted Phos. Acid, 60°. 



The most striking fact brought out by these tables is that the 

 Insol. Phos. acid is not stationary, but oscillates from week to week. 

 Thus from Table V it is seen that this oscillation of Insol. Phos. 

 acid is from a gain of .60 per cent, to a loss 1.22 per cent., the inter- 

 val between being four weeks. 



The oscillation of Insol. Plios. acid has been touched upon by J. 

 Post, (Chem. Industr. 1882, p. 217), who states, among other most 

 interesting facts, this, that during the first month the phosphates 

 which have become insoluble in water remain soluble in citrate at 

 40*^; but later on a part of the Reverted Phos. acid insoluble at 40^ 



