4 Experiments and Observations 
Vauquelin; according to him it consists of 
54 acid 
46 lime 
100 
From this analysis I was led to suspect that 
superphosphate was in reality a biphosphate, 
or two atoms of acid to one of lime; this no- 
tion would require it to be 
66 acid 
34 lime 
100 
but I soon found that the acid was in greater 
and the lime in less proportion than this, and 
that Vauquelin’s results were extremely wide 
of the trath. 
The first object that presented itself in this 
enquiry was to ascertain the component parts 
of calcined bones. Carbonic acid, lime and 
phosphate of lime I knew were found, but 
I did not know the exact proportions. By 
treating the calcined bones when pulverized 
with an excess of sulphuric acid, and weigh- 
ing before and after the effervescence, I re- 
peatedly found the loss of weight to be from 
2 to 8 per cent., which may therefore be con- 
sidered the proportion of carbonic acid. 100 
grains were dissolved in a minimum of nitric 
