38 EXAMINATION OF THE TEETH. 



One of the firft things to be attended to, was to procure 

 the enamel pure : this operation was not without difficulty as 

 will be eafily conceived, from the clofe adherence which this 

 fubftance preferves with the cfleous body, from the time the 

 germ of the tooth is developed aod ha? paifed through the re- 

 gular periods of the formation of the enamel, and of ofiifica- 

 tion. Neverthelefs, a fufficient quantity may be difengage4 

 from the bony part, by the afiiftance of chemical agents, 

 which, without producing any efTeft on the animal, act very 

 readily on the bone ; fuch are the means which will be point- 

 ed out, and which I have employed tq perform the expe- 

 riments I am about to defcribe. 



Having procured fome human teeth, as well as thofe of 

 feveral animals, I expofed them to the action of various che- 

 mical agents. 

 The enamel j then filed off the ename ii ed f ur f aC e of fome teeth, with- 



affbrded a very - a T" r i • 



(light indication out reaching the oueous part, I cauled the filings relulting 



pf gelatine. from this operation to be boiled in water, and I fubmitted the 

 liquor to the action oftanin. I obtained fo flight a preci- 

 pitate, that this operation fcarcely mowed the prefence of 

 gelatine. On the contrary, the ofTeous body, in the fame 

 proportions, and by the fame procefs, yielded an abundant 

 precipitate. 

 Papin^s algefter j expofed whole teeth in water, to a degree of heat fuperior 

 but not the ena- to tnat of ebulition, by means of Papin's digefler ; the enamel 

 jnel of teeth. preierved its hardnefs and its figure, but the bony part was, 



foftened and became friable. 

 The enamel does j n ' a naked fire, the enamel does not burn like a bone; the 

 t, one . fmell arifing from the igneous decompofition of an animal 



Aibftance, is fcarcely perceptible; it is not converted into 

 charcoal, but is (lightly browned and decrepitates. 

 DifVjllation ex- When carefully feparated from the body of the bone, and 

 tricates fcarcely dIftilled m t t thi f u bft anC e (hews only a faint trace of 

 any thing from . . J 



\u animal product ; it does not afford, like the bone, a great 



quantity of phlegm, of oil, of corbonate of ammoniac, or of 

 carbonate hydrogen gas ; and in all its phyfical and chemical 

 characters, it prefents differences which keep it diftinct from 

 the offeous body. 

 It Is foluble in However unfufceptible of change the enamel may appear 

 •"•*• to be, it is neverthelefs foluble in all the acids, but with re- 



markable differences, which depend on their radicals, their 

 3 concentration, 



