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VL Experiments and Obfervatlons on Shell and Bone. By 

 Charles Hatchett, E/q. F.R.S.* 



S 



OME experiments which I lately made at the reqneft of 

 Mr. Home, and which he has done me the honour to men* 

 tion in his ingenious paper on the teeth of granivorous qua- 

 drupeds, induced me to turn my attention more particularly 

 to the chemical examination of fliell and bone, efpecially as 

 the former appeared to have l)een hitherto much neglected. 



The time fince thefe experiments were begun, has not been 

 fufficient to enable me to enter into all the minutiae of the 

 chemical analyfis of thefe fubftances ; but, as fome remark- 

 able fa6ls were afcertained, I have now ventured to bring 

 them forward, with the addition of iomt obfervations, al- 

 though as yet the whole is little more than a very imperfect 

 outline. 



The firft of thefe experiments were made on the (hells of 

 marine animals ; and to avoid repetition and prolixity, I 

 iliall, in a great meafure, once for all, dcfcribe the menftrua, 

 the precipitants, and the mode of operation. 



When (liells were examined, they were immerfed in acetous 

 acid, or nitric acid, dilated, according to circumftances, wltli 

 four, five, fix, or more parts of dlftilled water; and the folu- 

 tion was always made without heat. 



The carbonate of lime was precipitated by the carbonate 

 of ammoniac, or of pot-afh ; and phofphate of lime (if pre- 

 fent) was previoufly precipitated by pure or cauflic ammo- 

 niac. 



If any other phofphate like that of fnda was fufpefted, it 

 was difcovered by folution of acetite of lead. 



Bones and teeth were alfo fubje6led to the a6lion of the 

 acetous, or diluted nitric and muriatic acids. 



The difTolved portion was examined by the above-men- 

 tioned precipitants ; and, in experiments where the quantity 

 of the fubflance would permit, the phofphoric acid was alfo 

 feparated by nitric or fulphuric acid. The phofphoric acid 

 thus obtained, w^s proved after concentration by experi- 



^ From the Fhilvfel'lical 'Tranfadions for 1799. 



ments, 



