together with iis Analysis. 241 
Analyses of Arragonite and of calcareous Spar by MM. Thenard an 
Biot. Mem. d’Arcueil, ii. 176. | 
. Arragonite. Calcareous Spar. 
Lime - = 56.351 e = 50.327 
Carbonic Acid = 42.919  - = 43.045 
Water Ze Ure a = 0.625 
100.000 — 100.000 
a a Sete 
Note,—Since the above observations were written, it has been 
again asserted, that the presence of Strontian in Arragonite has 
been ascertained by the German chemist before mentioned in 
p- 239, not as an adventitious mixture, but as an essential con- 
stituent. In answer to which I have only to observe, that in the 
specimens of Arragonite which I have subjected to analytical 
examination, I have never detected an atom of Strontian. Of 
course every thing must depend upon the purity of the specimens 
selected by the German Professor for his experiments. 
Cambridge, 
November 4, 1814, 
FU: Further 
