The Origin of Crystalline Rocks. 75 



deposits, and of some of the veins, warrants the introduction of 

 systematic mining by sinking, driving, and stoping ; with the aid 

 of proper machinery for drilling, as well as for hoisting and 

 pumping. The careful dressing and selection of the apatite for 

 the market is also an element of much importance in the exploita- 

 tion of these deposits. The cost of labor in the apatite-producing 

 districts is comparatively low, and there are great numbers of 

 beds now superficially opened, upon which regular mining opera- 

 tions, conducted with skill and a judicious expenditure of capital, 

 should prove remunerative. It must be added, that the areas in 

 question have as yet been very partially explored, and that much 

 remains to be discovered within them, and also there is reason to 

 believe in outlying districts ; so that in the near future the min- 

 ing of apatite in Canada will, it is believed, become a very 

 important industry. 



IT. The Origin of Crystalline Bocks.* 



By T. Sterry Hunt, LL.D., F.R.S. 



The author began by remarking that the problem of the origin 

 of those rocks, both stratified and unstratified, which are made up 

 chiefly of crystalline silicates, is essentially a chemical one. He 

 then proceeded to review the history of the once famous dispute 

 between the vulcanist and the neptunist schools in geology, as to 

 whether granite and other crystalline rocks were formed by igne- 

 ous or by aqueous agencies, and showed from recent writers that 

 the controversy is not yet settled. He noticed, of the igneous 

 school, both the plutonic and the volcanic hypothesis of the origin of 

 these rocks, and then proceeded to consider the metamorphic and 

 metasomatic hypotheses, which would derive them, by supposed 

 chemical changes, from materials either of igneous or of aqueous 

 origin. 



The hypothesis of Werner was next explained. This con- 

 ceives all such rocks to have been successively deposited in a 

 crystalline form from a chaotic watery liquid, which surrounded 



* Abstract of a paper read before the Royal Society of Canada at 

 Ottawa, May 20, 1884. 



