246 



SOLID PARTS OF ANIMALS. 



The following table exhibits the specific gravity of the enamel 

 of various teeth as determined by my trials : 



Human temporary tooth, 2-711 

 Human adult tooth, 2-688 



Hippopotamus, . 2'750 

 Elephant, . 2-843 



Mean, :*>; . 2-748 



The specific gravity of the ivory of various teeth is as follows : 

 Human temporary tooth, 2-090 

 Human adult tooth, 

 Cryptenopus Capensis, 

 Hippopotamus, 

 Walrus, 



Mean, 1-994 



The specific gravity of the decayed part of a human tooth was 



1-533. That of the crusta petrosa of an elephant's tooth was 



1-892. 



The following table exhibits the constituents which I extracted 



from the enamel of various teeth : 



Animal membrane, 



Subsesquiphosphate of] 



Carbonate of lime, 



Magnesia, 



Chloride of potassium, 



Chloride of sodium, 



Water, . . 0-98 



Sand, . 0-65 



1-005 



99-817 99-705 



0-14 



99-39 



0-63 



99-83 



entitled Mikroskopiska under sokningar ofver T'dndernes, s'drdeles Taribenets 

 struktur. It contains a very complete history of all that has been done on the 

 subject, together with numerous interesting observations of his own. 



When Mr Nasmyth's Researches on the development, structure, and diseases 

 of the teeth, at present in the press, make their appearance, we may expect a 

 great deal of new information j as he has been long and assiduously occupied 

 with the anatomy of these organs. His historical introduction already published 

 is very complete, and very interesting and instructive. 



* It is obvious from the result of the analysis, that this enamel was not pure, 



4 



