Apatite Bearing Rocks. 213 



three litres of sulphuric acid were used in the production of 

 sulphuretted hydrogen. A charge of acid and sulphide 

 placed in the "machine" last April and used a few times 

 remained in the apparatus during the holidays and in Sep- 

 tember, without any addition, produced a copious and 

 steady stream of sulphuretted hydrogen. The smaller ap- 

 paratus has been employed with equally satisfying results 

 for the production of hydrogen gas. 



The Apatite Bearing Rocks of the Ottawa 



District. 



R. W. Ells. LL.D., F.R.S.C. 



The present depressed condition of the foreign market 

 for phosphate has naturally tended to lessen the interest 

 which for some years pertained to the subject of Canadian 

 Apatite. But while this has been true to some extent, the 

 great amount of capital invested in this direction, and the 

 fact that the Canadian deposits are presumably among the 

 richest of their kind in the world, so far as yet known at 

 least, as well as the most convenient of access, will always 

 make the question of the availability of Canadian phosphate 

 one of very considerable importance both to the mining 

 and commercial communities. For while the immense de- 

 posits found in Carolina and Florida have, through their 

 cheapness of extraction and other causes, been largely re- 

 sponsible for the present unsatisfactory condition of this 

 industry, it is very doubtful if these southern sources of 

 supply will prove to be permanent or even remunerative 

 for any great length of time ; and unless other deposits, 

 equally extensive or accessible be found, attention must re- 

 vert to the Laurentian apatites as a source of supply for 

 this mineral fertilizer. 



Much nas been written from time to time on the subject 

 of Canadian apatites and their associated rocks by experts 

 from Canada, the United States and England, and the 

 literature in this direction, if collected, would form a fair 

 sized volume. Much of this has been reviewed and pub- 



