I 



in Animal Substances, S6i 



seous, translucent, of a pale yellow somewhat resembling 

 horn ; the outer, or enamel, is very white, breaks easily, and 

 has a rough fracture. "Ihc osseous portion is most observa- 

 ble on the upper surface of the tooth, where it forms trian- 

 gular figures having rounded angles, and passes in plates 

 even to the root of the tooth, filling up the spaces left by 

 the enamel. On examining these two substances, count 

 Morozzo conceived that thev must be difierent, and begged 

 M. Morichini to analvse them. This chemist soon dis- 

 covered, by the application of the sulphuric acid, that the 

 enamel of the molarfiS of the fossil elephant was alnyj^t en- 

 tirely compoj^ed of the fluate of lime, together with a small 

 proportion of the phosphate and carbonate of the same sub- 

 stance ; the. osseous substance, however, he found to be 

 principally formed of phosphate of lime. Such are the first 

 general results obtained by M. Morichini : tlii'v have been 

 published in the Memoirs of the Italian Society in this 

 imperfect state, as he had not then leisure to extend his? 

 experiments further. Since that time, however, he has^ 

 ascertained, with accuracy, the nature and proportions of" 

 the several substances composing the fossil tooth : he has 

 also analvsed the enamel of human teelh. M. Josse, as you: 

 well know, analvsed this last; but there was still a greau 

 deal to be done ; for his experiments offered no satisfactoiy 

 account of the difference existinc between the enamel and 

 the bony part of the tooth. As M. Morichini has a^.-ured 

 me his late experiments will certainly appear in the Memoirs 

 of the Italian Society, I shall not enter into any detail of 

 them, but merely relate the principal results. 



M. Morichini, having separated a portion of the enamel 

 of human teeth, and suspecting that it resembled in its 

 composition that of the molures of the elephant, treated it 

 in the same manner, and discovered, to his areat satisfac- 

 tion, that it contained a large proportion of iBuate of lime. 

 And to render his experiment more conclusive, he submitted 

 ^o the same tests the two enamels and the fluate of lime. 

 Under the action of the concentrated sulphuric acid, the 

 last of these three substances gave out readily copious va- 

 pours of fluoric acid : the enamel of the fossil teeth enutted 

 them rather more slowly, and that of human teeth with still 

 less rapidity. M. Morichini, however, rcniarks, that this 

 difference is whoiFv owing to the presenceoflm animal sub- 

 stance in the two enamels, which is n)ore abundant in that 

 of human teeth than in the enamel of the fossil; and to 

 prove it, he asserts that we may retard the disengagement 

 of the acid from fluate of hme by adding to it, after cnlcina- 



b tion. 



