EXAMINATION OF THE TEETH. 4| 



fcoated glafs retort. The fire was urged fo as to bring the 



retort to a red-heat, and after more than an hour, I remarked 



in the neck of it, a white fublimation, very light. This was 



the only product I obtained, and notwithstanding my care in 



keeping up the fire, no fluid was condenfed. 



When I judged that the operation was at an end, the ap- a fmall portion 



paratus was difengaged, and I haftened to examine the fublr- of whlte fubii - 



r , . , , r i ~ . r m ate, containing 



mate formed in the neck of the retort. J he quantity was lo f ome ammonia, 



fmall, that I had much trouble in collecting it ; it was dillblved 



by nitric acid. I then had reafon to believe that it was lime, 



volatized by the action of the fire ; never thelefs, as I had been 



itruck with a flight ammoniacal odour, I introduced into the 



neck of the retort, a match moiftened with muriatic acid, and 



I obferved that fome white vapours were quickly formed. 



Therefidue of the diftillation was a whitifh powder, whofe Refidue of lime 

 tafte was flightly cauftic : it was diflblved by water, and more 

 readily by acids, and changed tincture of violets to green. 

 Its folutiou, treated with different re-agents, yielded a true 

 lime. 



On reflecting upon the products obtained during the opera- Whether the 

 tion, I have given an account of, I thought I obferved a kind enamel be ox- 

 of analogy with thofe afforded by oxalate of lime. To fa- 

 tisfy myfelf how far this opinion might be well founded, I 

 determined to proceed in the analyfis of the enamel, according 

 to the method pointed out by Fourcroy and Vauqiielin, in the 

 interefting work published by them on urinary calculi, in 

 which they (hew that the fpecies of concretion called mural 

 ftone (pierre murale), is entirely formed of oxalate of lime 

 and an animal fubftance, 



I therefore pulverized fome enamel, and boiled a certain Enamel diflblved 

 quantity in liquid carbonate of potafh. The liquor was In P oUfl1, 

 fcarcely boiling, when I perceived a flightly penetrating 

 odour, nearly refembling that of ammonia. I then introduced 

 into the neck of the matrafs, a paper match, dipped in con- 

 centrated nitric acid ; immediately an abundant vapour was Ammoniacal 

 formed, fuch as is always feen when ammoniacal gas is brought va P 0Ur * 

 into contact with that difengaged from nitric acid. 



When the ammoniacal odour had ceafed, I withdrew the 

 matrafs, and placed it on a fand-bath. After twenty-four 

 hours digeftion, I found at the bottom of the matrafs, a white 

 precipitate^, above which floated a limpid liquor -, it was de- 

 canted 



