m Analysis of the Human TeefH. 



tioned : these solutions yield, wilh a soltitiou of acetite of 

 lead, a copious precipitate, proving the presence of phos-r 

 phoric acid. 



The precipitate obtained by the carbonate of ammonia is 

 also soluble in either of the above acids, but with efferves- 

 cence ; and these solutions are not precipitated by acetite 

 of lead ; they fall, however, with oxalate of ammonia, car- 

 bonate of ammonia, ot anv precipitant of lime. 



The great solubility of the phosphate of lime, in even the 

 weakesrof the acids, is very extraordinary. Phosphate ot 

 lime mechanically suspended in w ater is speedily and com- 

 pletely dissolved by passing a copious &tream of carbonic 

 acid gas through it. 



With these facts before me, I have ventured to examine 

 the several specimens of the humail teeth ; as the enamel, 

 the bone, or roots, the teeth of adults, and the shedding 

 leeth of children .^ 



Previous to an account of the analysis it may not be un- 

 interesting to notice the action of some of the articles of the 

 materia chemica on the teeth. 



Sulphuric acid of the specific gravity 1'83 appears at fir^t 

 tO' have no action ; in the course of an hour small bubbles 

 are perceived, the roots beconie blackened, and. in twelve? 

 hours the enamelled part bursts, cracks, and separates,, ac- 

 companied with an evident formation of selenite, by the 

 action of the acid on the lime, which enters into the com- 

 position of the teeth. 



Nitric and muriatic atids of the specific gravity of ri2 

 act instantly on the tooth, accompanied witli an cvolutioa 

 «f a quantity of small air-bubbles from the whole of the sur- 

 face; about eight times their weight of these acids are suffi- 

 cient for the solution of the solidifying principles of the 

 teeth.. The mass left undissolved has nearly the original 

 form of the tooth, is flexible, semitransparcnt, and easily 

 divided by the nail. 



The dilute acetous acid (distilled vinegar) has a very tri- 

 fling action, but, when concentrated, acts both on the phos- 

 phate and carbonate of lime. 



Boiling nitric acid acts strongly on a tooth with the evo- 

 lution of carbonic acid and a considerable quantity of azotic 

 gas. The gelatine and solid substance are dissolved as tlu; 

 surfaces present themselves; but the operation bting stopped 

 at any part of the process, the residuum is firm and hard,, 

 but reduced in size profioitioned to tlic time the tooth ha^ 

 been acted upon, 



• jinalysis. 



