THE MASTODON. 21 



such a depth as to prevent the contact of air, and in other 

 cases are protected by superincumbent earth which resists 

 the tendency to decomposition. In the salt-licks it is due 

 to their having been impregnated with the chloride 

 of sodium, which has a greater power of preventing de- 

 composition than ordinary soil. 



Dr. C. T. Jackson made an analysis of a portion of the 

 vertebral bone of the Newburgh skeleton, after being dried 

 at 300° Fahr., with the following result : 



"Animal matter (bone cartilage) 27.73 



Bone earth (phosphate and carbonate of lime) and phos- 

 phate of iron 72.27 



100.00 

 "A portion of the bone with cancelli yielded, by drying, 

 at a little above 212° Fahr. 



Water G 



Bone earth (phosphate and carbonate of lime) and phos- 

 phate of iron 04 



Bone cartilage 30 



100 



" On burning the bone, the ash which remains is of a 



beautiful blue color, owing to the presence of phosphate 



of iron, which appears to have been infiltrated into the 



bone from the marl surrounding the skeleton." 



One of the skeletons found in Wythe county, Virginia, 

 preserved the outlines of its trunk, and another in Illinois, 

 the fleshy part of the mouth in a tolerably good condition. 



VI. THE TEETH. 



The vast number of teeth which have been discovered 

 in a good state of preservation, received early attention, 

 and their structure and form have aided very materially 

 in assigning to the mastodon its true position in the econo- 

 my of nature. The teeth are nearly rectangular in form, 

 and present, on the surface of their crown, great conical 



