In 1917, 38,831 oz. of refined platinum metals, of which 7,384 oz. is believed to have been of domestic origin, were recovered from alloy with other metals, and 72,186 oz. were obtained from the refining of scrap metal, and sweepings. The shortage was also to some extent relieved by the receipt from Russia early in 1918 of a special consignment of 20,922 oz. of crude platinum, which had been collected in 1917 by the Russian-English Bank, and which was taken out of Russia by F. W. Draper and delivered to the United States Government. It yielded 17,640 oz. platinum, 64·75 oz. palladium, 182·11 oz. iridium and 48·56 oz. of rhodium, a total of 85·725 per cent. of platinum metals, slightly above the usual 83 per cent.[65]. _Alaska._—The first production of platinum in Alaska was in 1916, in which year about 12 oz. were shipped to the United States. In 1917 the output rose to 81 oz., of which 66 oz. were obtained from the Seward Peninsula and 15 oz. from the Copper River country. In 1918 an increased output of 135 oz. was partly obtained from alluvial deposits and partly as a by-product in the treatment of copper ore of the Salt Chuck mine, Ketchikan[66]. This mine is a palladium-copper mine containing mainly bornite with a little chalcopyrite, and the alteration products covellite and chalcocite, the metals present being, besides copper and palladium, gold, silver and platinum. The ratio of palladium to platinum averages 50 to 1. The concentrates produced, representing about 3½ per cent. of the weight of the ore, contain: copper, 40 per cent.; gold, 1·2 oz.; silver, 5·3 oz.; and platinum metals, 3·15 oz. per ton[67]. In the Seward Peninsula the larger portion is derived from placer deposits in Dyme Creek, Koyuk district, where the gravels are primarily worked for gold, 1 oz. platinum being obtained for every $5,000 worth of gold. In 1918, 56 oz. were recovered. Bear Creek and Sweepstake Creek have also supplied small quantities of platinum, and a little is derived from placers on Boob Creek, in the Tolstoi district [50] p. 19. A possible source of platinum appears to lie in the neighbourhood of the Red Mountain, on the Kenai Peninsula. The mountain is composed of fine-grained dunite, in which abundant chromite occurs. Up to 1917 no placer mining had been attempted in this locality[68]. In the Goodro Mine, at the head of Kasaan Bay, Prince of Wales Island, were found in 1918 both platinum and palladium, the latter in greater amount, and carried in bornite and chalcopyrite; some chalcocite and covellite are present also in the ore. The copper minerals are disseminated through pyroxenite, and the country rock consists of limestones, slates and other sedimentaries. The platinum content is small, but regular, whilst the amount of palladium present is proportional to the amount of copper, there being about 1 oz. of palladium to every 8 to 12 per cent. (units) of copper[69].