and Observations on Shell and Bone . 327 
of acids, an effervescence, although at times but feeble, was 
produced. This circumstance, at first, I did not particularly 
notice, but the following experiments excited my attention. 
After the phosphate of lime had been precipitated from the 
solutions of various teeth and bones, by pure ammoniac, I ob- 
served, that a second precipitate, much smaller in quantity, was 
obtained by the addition of carbonate of ammoniac. This se- 
cond precipitate dissolved in acids, with much effervescence, 
during which, carbonic acid was disengaged; and selenite was 
formed by adding sulphuric acid. Moreover, the solution of this 
precipitate did not contain any phosphoric acid; nor did the 
liquor from which the precipitate had been separated afford any 
trace of it. 
This precipitate was therefore carbonate of lime ; but I still 
was not certain that it existed, as such, in the teeth and bones. 
Although regular and comparative analyses of the bones of 
different animals have not hitherto been made, yet, by the ex- 
periments of Messrs. Gahn, Scheele, Macquer, Fourcroy, 
Berniard, and the Marquis de Bullion, it has been proved, 
that phosphate of lime is the principal ossifying substance of 
bones in general, and that this is accompanied by a small pro- 
portion of some saline substances, and by sulphate of lime. 
I was therefore desirous to ascertain, whether the carbonate 
of lime which I had obtained by the abovementioned experi- 
ments, had been produced from the sulphate of lime decom- 
posed by the alkaline precipitant, or whether the greater part 
had not existed in the bones, in the state of carbonate. 
Each of the solutions in nitric acid afforded a precipitate with 
nitrate of barytes ; but the quantity of sulphuric acid thus se- 
parated, appeared by far too small to be capable of saturating the 
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