MICA AND THE MICA MINES. 665 



ors on glass and porcelain. The peculiarly fine black of Havi- 

 land china is due, I believe, to uranous oxide. 



The Ural Mountains are the collecting-grounds for the cabi- 

 nets of Europe. In no other district can one find so many varie- 

 ties of minerals within the same area. The mountains of western 

 North Carolina are in many respects similar. They probably 

 yield a greater number of rare minerals than any other region in 

 America, and are therefore a favorite tramping-ground for col- 

 lectors. At the smallest cross-roads post-office one hears of the 

 visit of some well-known mineralogist. Nearly every mountaineer 

 has a few specimens in his treasury, and generally he knows the 

 names of the more characteristic varieties, particularly if they 

 have a marketable value. It is not safe, however, to rely very 

 implicitly upon his classification, for his knowledge is of the most 

 superficial sort. 



As commonly taught in our schools and colleges, and as com- 

 monly apprehended by students outside, a knowledge of mineral- 

 ogy consists of a more or less definite familiarity with several 

 hundred minerals, and an ability to recognize the more common 

 varieties on sight, or by means of some readily applied physical 

 test. It is largely a knowledge of separate and unrelated facts, a 

 catalogue, one might almost say, and not yet a body of well-or- 

 ganized truth. We have gathered part of the material of a fine 

 science, and eminent men are now at work building this material 

 into a coherent whole. The curious facts of paragenesis, or the 

 characteristic associations of minerals, and the many problems 

 presented by substitution and alteration, are being carefully in- 

 vestigated. The mysteries of crystallization are commanding 

 attention. The progress along these lines is very encouraging. 

 But a great amount of work still remains to be done. One who 

 comes to the study of minerals at this particular juncture will 

 find it pleasurable, even as a study of separate facts, but he will 

 feel, I think, that a greater pleasure remains for him when these 

 results have been still further co-ordinated. We are still waiting 

 for our Darwin. 



Statistics concerning the influence of the style of living on stature, collected by 

 M. G. Cartier from among the conscripts at IJvreux, France, go to confirm the 

 conclusions that other authors have drawn on the subject. Persons who are sup- 

 posed from their occupations to have been brought up under good hygienic condi- 

 tions and comfortable circumstances students, farmers, etc. are generally of 

 larger than average stature ; while persons ill-fed, poorly clothed, or who have 

 grown xip in an unfavorable medium workers in metallurgy, weavers, etc. 

 are smaller. Consequently, if u the race fixes an ideal mean round which indi- 

 viduals oscillate," the latter are especially influenced by the conditions of the 

 medium, alimentation, exercise, and comfort. 



