[27] A. Lodin, Comptes rendus, 1895, CXX, 1164-1167; Berg. u. Hüttenm. Ztg., 1903, p. 63.
[28] Comptes rendus, loc. cit.
[29] Translated from the Zeitschrift für das Berg.-Hütten-und Salinenwesen im. preuss. Staate, 1905, LIII, ii, pp. 219-230.
[30] Translated from the Zeitschrift für das Berg.-Hütten-und Salinenwesen im. preuss. Staate, 1905, LIII, ii, pp. 219-230.
[31] The manufacture of sulphuric acid from these gases has now been undertaken in Silesia on a working scale.—Editor.
[32] A paper presented before the American Institute of Mining Engineers, July, 1906.
[33] Engineering and Mining Journal, Sept. 2, 1905.
[34] This term is inexact, because the hearths employed in the United States are not strictly “Scotch hearths,” but they are commonly known as such, wherefore my use of the term.
[35] Percentages of lead in Missouri practice are based on the wet assay; among the silver-lead smelters of the West the fire assay is still generally employed.
[36] This improvement did not originate at either Alton or Collinsville. It had previously been in use at the works of the Missouri Smelting Company at Cheltenham, St. Louis, but the idea originated from the practice of the Picher Lead Company, of Joplin, Mo.