^ncdi/sis pf, {he J^uman Tee(h, 31s 



Analysis of the. En am el. 



One hundred grains of the enamel of human teeth, care- 

 fully rasped, were' placed in 600 grains of nitric acid of the 

 specific gravity ri2. Slight effervescence ensued, and after 

 twelve hours 200 grains more of the acid were added. Al- 

 lowing for the loss by.eyaporation in a corrcsppudlng vessel, 

 after thirty-six houTs it was found to have lost four grainx 

 and a half. 



It was then diluted with fovir ounces of distilled water, 

 precipitated by pure anjmonia, .and then, filtered... . 



The precipitate obtained being dried in a water-bath ai 

 21 2° weighed 10^2 grains. It was then ignited^ after which 

 it was found to weigh 78 grains. 



The filtered solution was then precipitated by carbonate 

 of ammonia in solution, and filtered. 



The separated precipitate, being dried in. a. heat of 212?* 

 •^vcighed six grains, EnariieT, then, consists of 



Phosphate of lime - - 78 



Carbonate of lime - - 6 



84 

 AVater of composition, and loss - 1 6 



100 



A loss of 16 grains here talces place, which is easily ac- 

 counted for, from the impossibility of directly ascertaining 

 the state of dryness in which the ingredients existed origi- 

 nally in the enamel'; for we have seen that, by drying the 

 pliosphate of lime in a heat of 212", (after which it had the 

 appearance of being as dry as possible,) it yet contained so 

 much moisture as to yield a gain of eight grains in the 

 iipalysis. 



Ori the other hand, when ignited its state is driven to 

 the opposite extrcinc, and there is a loss of 1(5 grains. It 

 is impossible, however, that the materials could exist in the 

 tectli, in a state of dryness to be compared with that pro- 

 duced by exposing them to such a high temperature. And 

 if appears but reasonable to conclude, that the real quantity 

 of moisture lies nearer to that given by the heat oi' 2 1 2* 

 than to that given by ignition, and consequently that the 

 it) grains lost by exposure to such a high temperature were 

 Cliicfly water, 



Bone, 



