per cent of manganese, whereas most of that shipped in 1922 contained 45 to 53 per cent and therefore brought a higher price. Montana, as usual, shipped the largest quantity. Figures for gross weight of manganese ore imported have not been recorded by the Bureau of Foreign and Domestic Commerce since the change in the tariff, but the Survey estimates that the imports of such ore in 1923 were 419,000 long tons. These imports are less than those in 1918, when the domestic production was nearly 10 times as much as in 1923. In 1918 the production plus imports amounted to 797,000 long tons, compared with approximately 451,000 tons in 1923. These figures do not indicate a decrease in the requirements for manganese, however, for the production of steel almost equaled the production in the record year. The conditions thus shown are due to the facts that the imports of ferromanganese in 1923 were large and that manganese ore had been imported and stocked at the furnaces in 1922, prior to the date the new tariff went into effect.

Of the remaining metals of industrial importance, aluminum and arsenic were conspicuous in 1923, as they had been in 1922, by reason of large increases in production. The problem of arsenic supply continued to be of prime importance. During 1923 production was expanded to meet anticipated requirements, and production plus imports succeeded in keeping pace with the growth in demand. The close balance between supply and demand resulted in an increase in prices late in the year, when those consumers who had not early closed contracts with the larger producers began to buy eagerly. Of the total arsenic output 90 per cent came from lead and copper smelters. Of this amount only about one-half was a direct by-product from smelting lead and copper ores during the year, the remainder being derived from arsenical materials accumulated at the smelters through a number of years of operation and from the treatment of ores especially selected for an arsenic content higher than that in ores normally treated at the smelters. The older accumulations of flue dust and speiss were greatly depleted during the year and were practically exhausted during 1924, so that future supplies of arsenic from the smelters became dependent upon purchase of arsenical ores. Plants for the direct production of white arsenic showed increased output in 1923 and thereafter produced from ores treated directly for arsenic a much larger share of the total supply than they had before contributed.

In the field of production of nonmetallic minerals other than fuels sharp increase over the output of 1922 was general. This was the more noteworthy in that the production records for 1922 generally showed very considerable increases from 1921. As a result the rate of production in 1923 for most of these minerals was on a par with, and for some even exceeded, the peaks reached during the period of war stimulation. The minerals entering the chemical and metallurgical industries showed increases ranging from 5 per cent for common salt to 164 per cent for magnesite. Shipments of sulphur increased 20 per cent; the output of natural sodium salts (other than NaCl), 31 per cent; barite, 38 per cent; and chemical lime, 16 per cent. Shipments of fluorspar, chiefly flux, decreased 14 per cent. Among the fertilizer minerals phosphate rock increased 24 per cent

in shipments; potash, 70 per cent; and available lime in burned lime, pulverized limestone, and calcareous marl, used for agriculture, 5 per cent. The principal mineral materials used in the ceramic industries-clays, feldspar, glass sand, and silica of other varietiesshowed moderate to large increases. The advance in the construction industries is reflected by increases in the mineral products they use, slate gaining 20 per cent; cement, 16 per cent; stone in general, 29 per cent; and sand and gravel, 48 per cent.

The abrasive materials as a whole showed a very large increase in 1923, and so also did graphite, mica, and fuller's earth.

Mineral products of the United States in 1922 and 1923.

Quicksilver (value at San Francisco).

d Product from domestic ores only.