The origin of the ore bodies has not yet been settled. They are either marginal deposits in, or off-shoot deposits to, a norite laceolith, which has intruded sedimentary rocks, the ores consisting principally of chalcopyrite, pyrrhotite, and pentlandite. Metallic platinum, gold, silver and palladium occur in the ore, the last also, probably, as an arsenide. The highest platinum content is associated with the highest copper content; the highest palladium with the highest nickel. According to Roberts and Longyear[36] the mean analysis of rocks of from sixteen drill holes gave an average ore content of: copper, 1·11 per cent.; nickel, 1·95 per cent.; silver, 0·223 oz.; gold, 0·022 oz.; and metallic platinum, 0·0068 oz. per ton. The ore is principally worked for its nickel and copper content, and yields a large proportion of the world’s supply of nickel. The ore is first smelted at the mines, and a portion of the low-grade matte so produced is then shipped to South Wales for final treatment, the remainder being sent to the recently-constructed refinery of the International Nickel Co., at Port Colborne, Ontario, and to the United States. It was stated in 1903 that this matte contained on the average 1·25 oz. of the platinum metals per ton of nickel content of the matte, of which about 80 per cent. was extracted[37] p. 10. The Victoria Mine, owned by the Mond Nickel Co., is stated to carry a high percentage of the precious metals, as is also the Vermilion Mine, although in the latter case the ore body is very small. In 1917 the total output of copper-nickel ore from these deposits amounted to 1,506,828 tons, of which the Canadian Copper Co. raised 1,139,629 tons, the Mond Nickel Co. 361,335 tons, and the Alexo Mining Co. 5,864 tons. The nickel content of the ore of the Canadian Copper Co. was about 2·5 times that of the copper, whilst the ore mined by the other two companies contained the two metals in approximately equal proportions. The matte produced by the Alexo Mining Co. is smelted by the Mond Nickel Co. According to the report of the Royal Ontario Nickel Commission, the matte produced by the Canadian Copper Co. in 1916 was estimated to contain 4,640 oz. platinum and 8,460 oz. palladium, corresponding to 0·10 oz. platinum and 0·15 oz. palladium per ton of matte, the International Nickel Co. recovering in that year 1,093 oz. platinum and 257 oz. allied metals. This company is now reported to have improved its methods of recovery. In 1918 the total matte shipment by the Canadian Copper Co. is stated to have contained, among other precious metals, 8,677 oz. platinum and 13,016 oz. palladium[38]. According to information supplied by the Mond Nickel Co., their nickel residues derived from the refining of the matte are taken over by Johnson, Matthey & Co., Ltd. During the years 1915–18 the residues disposed of were estimated to contain the following amounts of platinum metals: