282 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



winter, that the aborigines by whom they were constructed 

 must have been decided cannibals, as in eight different in- 

 stances he has found considerable quantities of human bones 

 in the shell heaps, the bones themselves being broken up and 

 split, just as in the case of the bones of other animals. This, 

 he is satisfied, was not the result of burial, but was done for 

 the purpose of obtaining the marrow, probably after the flesh 

 had been devoured. 



WORKING OF MICA MINES IN NORTH CAROLINA IN PRE- 

 HISTORIC TIMES. 



Among the rarer and more interesting remains found in 

 the mounds of the West are plates of mica cut into different 

 shapes, and evidently preserved as objects of great rarity and 

 value; and, in the absence of this mineral in the Mississippi 

 Valley, the question has frequently arisen whence the mate- 

 rial could have been derived. 



A recent communication from Professor W. C. Kerr, the 

 State Geologist of North Carolina, tends to throw some light 

 on this subject, and to open an interesting chapter in regard 

 to the American prehistoric man. The use of mica in the 

 arts, it is well known, has been increasing very rapidly for 

 the last few years, and the old localities have become in a 

 measure exhausted. This has made it necessary to search 

 out new deposits of the mineral, and it is in North Carolina 

 that the finest and largest plates of this substance have been 

 met with. The work of collecting mica is carried on upon 

 the largest scale in the high and rugged region between the 

 Black Mountain, the Roanoke, and the head waters of the 

 Nolachucky, principally in Mitchell County, North Carolina. 



The region in question has long been known for the exist- 

 ence of numerous open works and tunnels, which, at first 

 sight, were supposed to have been made in the search for sil- 

 ver or other valuable metal. Professor Kerr, in his capacity 

 of State Geologist, was led to investigate this question, and 

 very soon found, in every instance, that the excavations re- 

 ferred to were much older than the earliest discovery of the 

 country by the Spaniards, and that in all cases they were 

 found in ledges of coarse granite, which contained nothing 

 but large patches of mica. So uniformly was this the case 

 that, after a while, the search for mica mines Avas mainly con- 



