THE TUSKS. 87 



eleven inches long ; but, being broken soon after exhumation, the anterior Length of 



Superior 



termination of each only, in length about four feet, and in diameter at the Tusks. 

 truncated extremity five inches, remains in a perfect condition. The middle 

 portion, of rather more than two feet, has crumbled. The posterior portion, 

 of about the same length with the anterior, is broken into lamina? ; it is 

 flattened at the base, so as to be half an inch longer in one diameter than 

 in the other, making the largest seven inches and a half. The bases are 

 surrounded externally by circular elevations, at first two inches distant from 

 each other, but gradually increasing in distance, until, at about two feet 

 from the extremities of the bases, they disappear entirely. 



The tusk is composed of lamina?, which, at the internal extremity of structure. 

 the socket, are not more than a line in thickness. These lamina? increase 

 in number as we advance from the butts, so that, where the tusk issues 

 from its socket, at the distance of rather more than two feet from the 

 posterior extremity, the internal cavity has diminished from seven inches 

 in diameter to two by two and a half. The plates into which the tusk has 

 separated in drying are generally an eighth of an inch in thickness, some 

 of them nearly an inch. The external surface has a brown appearance ; 

 the layers which have been recently uncovered are of a lighter color. 



The following analysis of a portion of the tusk has been kindly fur- 

 nished me bv Dr. Charles T. Jackson : — 



" Animal matter (cartilage) 26.2 Analysis. 



Phosphate and carbonate of lime, fluoride calc, &c 69.2 



Water 4.6 



100.0 



" Glass was etched with the fluorine. The constituents of the tusk are phosphate of lime 

 carbonate of lime, fluoride of calcium, phosphate of magnesia, soda, sulphur." 



