Canadian Forestry Journal, April, ipi6. 



479 



thousands of mountain streams, 

 should, when finished, rank with the 

 great constructive pubhc works of the 

 world. The task is now half com- 

 pleted. The cost up to 1909 was 



$20,650,000. The estimated cost for 

 the remainder of the w^ork in sight 

 w^as then $12,000,000. exclusive of up- 

 keep and exclusive of the expenditure 

 necessary by departments, communes, 

 and private individuals. Such works 

 hozvever, should not he measured by 

 cost, but by results. The oblitera- 

 tion of the torrents of France, impos- 

 sible as it may have appeared in the 



beginning, will he practically accom- 

 plished with the completion of the pro- 

 gramme .nozc .adopted. Torrential 

 floods, ivhich in one year z^'r ought de- 

 struction equal to the total cost of 

 stream improvement, will be no longer 

 possible, and neither the vineyards and 

 farms of the lozi'er z'alleys, nor that 

 important mountaineering element of 

 the population zvhich clings to upland 

 slopes and z'alleys zcill hereafter be 

 in danger by flood or snozcslide. The 

 price of one year's flood carefully ex- 

 pended zvill permanently add millions 

 of acres to the productive area of 

 France. 



The Use of Pine Oils in Treating Ores 



Much interest has been exhibited 

 in the application of what is called 

 the "pine oil flotation process" to 

 the treatment of ores in the Cobalt 

 mining district. At present the 



scope of the process in Canada is 

 confined to experimental work, al- 

 though flotation has been in use at 

 many of the big United States silver 

 and copper mines for years past. 



The apparent economy and sim- 

 plicity of the process, which may 

 give high value to the enormous 

 quantity of tailings of the Cobalt 

 and other mines at present regarded 

 as waste, depends upon an assured 

 supply of pine oil. This is now im- 

 ported from the United States and 

 no guarantee of more than a few 

 months' supply can be had. Wheth- 

 er or nof the Canadian mines can 

 be made independent of imported 

 oils for the flotation process is at 

 present engaging the attention of 

 experts identified with the Ontario 

 and Federal Governments and ex- 

 periments will be made at the For- 

 est Product Laboratories, Montreal, 

 along such lines. If Red Pine or 

 other Canadian woods could be 

 made to produce the quality and 



quantity of oils required, a new^ in- 

 dustry might be added to these now 

 identified with the Canadian forest. 



The system apparently is simpli- 

 city in itself yet there are things 

 about it wdiich cannot be explained 

 even after exhaustive research work 

 which is now being carried on. The 

 principle is that air is forced under 

 pressure through the canvas l:)Ottom 

 of a tank-like cell, through wdiich 

 cell emulsified oil and water mixed 

 with crushed ore held in suspension 

 passes. The oil apparently forms a 

 filament on the particles of mineral 

 and brings them to the surface in 

 the bubble. The froth is skimmed 

 off and in it is contained the mineral. 



The oils used may be broadly di- 

 vided into "frothers" and "collec- 

 tors." The pine oils are good froth- 

 ers and coal tar and its various sub- 

 divisions are good collectors. It 

 has been found that a mixture of 

 coal tar. 50 to 60 per cent., coal tar 

 creosote 30 to 40 per cent., and re- 

 fined pine oil 5 to 10 per cent, give 

 good results. Other pine oils work 

 very well on Cobalt ores, however. 

 The oil consumption per ton of ore 

 approimates about one pound or 

 from 2 to 3 cents per ton of ore. 



