a The
consumption of potassium cyanide was 185,764 pounds in 1916,137,658
pounds in 1917, 625 pounds in 1918, 68,155 pounds in 1919 (17,884
pounds at mills in Arizona and 50,271 pounds at mills in Nevada), and
7,825 pounds in 1920 (7,800 pounds at mills in Arizona and 25 pounds at
mills in Washington).
b Includes some cyanamid.
It
has not been possible to obtain figures showing the total consumption
of potassium cyanide and sodium cyanide used in the recovery of gold
and silver in the United States in 1920. If the quantity used in
California, Alaska, and Oregon is added to the 2,878,691 pounds
reported to have been used in other Western States the total
consumption was probably about 3,300,000 pounds.
ACKNOWLEDGMENTS.
To
those engaged in the mining and mctallurgic industries, to merchants,
bankers, and transportation officials of the United States and Alaska,
to the Bureau of the Mint, the Post Office Department, and the Bureau
of Foreign and Domestic Commerce of the Department of Commerce, and to
other officials, public and private, who have cooperated with the
United States Geological Survey by furnishing information on the
production of gold and silver, acknowledgment is gratefully made. To
the authors of the Survey mines reports on the production of gold,
silver, copper, lead, and zinc in the Western States and in Alaska the
writer is especially indebted.
