produced for the year 1905. For 1904 the following plan has been adopted. The gold and silver product is classified according to its derivation from placers, dry or siliceous ores, lead ores, copper ores, and zinc or zinc-lead ores.
The placers include the sluicing, hydraulic, dredging, and drifting prooesses.
The smelters designate as dry ores those with less than 5 per cent lead, which usually are chiefly valuable for their gold and silver. Under the heading of dry or siliceous ores are included quartzose gold and silver ores with less than 4£ per cent lead or 3 per cent copper, which are usually treated by amalgamation or cyanide process. But it is also necessary to include with them certain low-grade ores which are less clearly quartzose in character, such as the calcareous cyanide ores of Fergus County, Mont. Ores with over 4^ per cent lead are designated as lead ores, and ores, with over 3 per cent copper as copper ores. In the latter case the difficulty is that small parcels of gold and silver ores which contain 3 or 4 per cent of copper ore are not considered as copper ores by the smelters, and no pay is obtained for the metal; while, on the other hand, in some very large pyritic copper mines, as in Butte, Mont., the grade of the regular ore is apt to sink below 3 per cent copper. Those ores are classed as zinc ores, which are chiefly valuable for the zinc contained, or, if they contain both lead and zinc, those in which the value of zinc predominates over that of the lead. They are usually lacking in gold and poor in silver. The greatest difficulty is presented by the Leadville ores, which contain gold, silver, copper, and lead, and often not enough of any one of these metals to pay for reduction. It is often a matter of doubt as to whether such an ore should be classed as dry and siliceous ore, as lead ore, or as copper ore. Concentrates of regular dry and siliceous ores, even if containing lead or copper, are not considered as lead or copper ores, because the classification is based on the quality of the ore as mined.
DISTRIBUTION OF GOLD PRODUCT OF 1904.
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Gold from placers. The placer gold obtained in 1904 was to the amount of 612,631 fine ounces, equivalent to $12,664,206.
Alaska and California are of course the largest producers. With an output of 290,276 ounces, nearly one-half of the total, Alaska shows a small loss in placer gold compared with 1903, in spite of greatly increased output from the Tanana diggings. California has gained much more in placer yield compared with 1903, in fact 45,115 ounces, or $932,529. This is chiefly due to dredging, the amount derived from this industry increasing steadily from $200,000 in 1900 to $2,187,038 in 1904. The principal productive area extends from the Klamath
