on Phosphoric Acid. 9 
phosphate. 'That is, it consists of 8 atoms of 
acid and 1 of lime, or of 12 atoms of acid 
and 1 of lime.* 
The octophosphate would be constituted of 
acid 88%. 
lime 114 
100 
‘The dodecaphosphate would be constitut- 
ed of acid 92 
lime 8 
100 
Hence then it appears that this superphos- 
phate of lime is almost entirely phosphoric 
acid; and as it seems that one pound of it 
in the strongest liquid form may be obtained 
from 27 lb. sulphuric acid and 3 lbs. calcined 
bones, it is obvious that the labour and ex- 
* T am not quite satisfied whether the ultimate effect of 
sulphuric acid is to produce an octophosphate or dodeca- 
phosphate of lime, but incline to the former. I have adopt- 
ed two modes of investigation; namely, to precipitate the 
remaining lime by oxalic acid; and to saturate the super- 
phosphate by lime water; the former of these involves the 
question whether oxalic acid, even in excess, will precipi- 
tate the whole of the lime; the latter, which is perhaps 
preferable, requires 1 desatn measures of quantity in the 
elements of phosphate of lime. 
VOL. Il. B 
