en Shell and Bo7ie* '^^^ 



pcriments, had been produced from the fulpliat of lime de- 

 compofed by the alkaline precipitant, or whether the greater 

 part had not exifled in the bones in the (late of carbonat. 



Each of the foiutions in nitric acid aflbrded a precipi- 

 tate with nitrat of barytes ; but the quantity of fulphuric acid 

 thus feparated appeared by far too fmall to be capable of fa- 

 turating the whole of the carbonat of lime obtained from aa 

 equal quantity of the folution. To prove, therefore, the pre- 

 fence of the carbonic acid, and the conl'equent formation of 

 carbonat of lime, portions of the various teeth and bones 

 were immerfed at feparate times in muriatic acid ; and the 

 gas produced was received in lime-water, by which it was 

 fpeedily abforbed, and a proportionate quantity of carbonat 

 of lime was obtained. 



Although it appears that the principal effefts during ofli- 

 fication are produced by the phofphat of lime, yet we here 

 fee that not only fome fulphat, but alfo fome carbonat of lime 

 enters the compofition of bones ; and it is not a little curious 

 to obferve, that as the carbonat of lime exceeds in quantity 

 the phofphat of lime in cruftaceous marine animals and in the 

 egg-fliells of birds, fo in bones it is i<lce verfa. It is poflible, 

 when many accurate comparative analvfesof bones have been 

 made, that fome may be found compoied only of phofphat of 

 lime; and that thus fliells containing only carbonat of lime, 

 and bones containing only phofphat of lime, will form the 

 two extremities of the chain. 



I fliall now make a few remarks on the enamel of teeth. 



When a tooth, coated with enamel, is immerfed in diluted 

 nitric or muriatic acid, a feeble effervefcence takes place, and 

 the enamel is completely diflolved; fo alfo is the bony part; 

 but the cartilage of that part is left, retaining the fliape of the 

 tooth. Or if a tooth, in which the enamel is intermixed 

 with the bony fubftance, is plunged. in the acid, the enamel 

 pnd the bony part are diflolved in the fame manner as be- 

 fore ; that is to fay, the enamel is completely taken up by 

 the acid, while the tooth, like other bones, remains in a 

 pulpy or cartilaginous llatc, having been deprived of the 

 oflifying fubilance, Confequently, thofe parts which were 

 coated or penetrated by lines of enamel are diminiflied in 



proportion 



