on Phosphoric Acid. 3 
With regard to the proportion of lime and 
phosphoric acid in phosphate of lime, autho- 
rities do vary a little; but the most modern 
nearly accord with each other. 
acid base 
According to Vauquelin 41 ++ 59100 phosphate of lime 
Klaproth 45 + 59 
Davy 48 + 52 
Berzelius 50.8 + 49.2 —_-—— 
My experience 49 + 51 ————_—_ 
Hence we may conclude that phosphate of 
lime is constituted of nearly equal parts of 
acid and lime. The weights of the respec- 
tive atoms are, of acid 23, of lime 24, as 
given at pages 415 and 508 of my chemistry, 
Vou. 1; and succeeding experience has fur- 
nished me with no cause for a variation of 
‘these numbers. 
Any one may easily satisfy himself on this 
head; he has only to saturate by degrees a 
given quantity of lime water with phosphoric 
acid, then filter, and expose the precipitate to 
a red heat; when it will be found the phos- 
phate weighs rather less than double that of 
the lime in solution. A very minute portion 
of phosphate of lime remains in solution; 
but it is too minute to deserve notice. 
No author that I know of has published an 
analysis of superphosphate of lime, except 
