Rossiter W. Raymond

“ The rich Spanish silver mines were developed at an early day, and furnished the main supply of the metal for Phœnicia, Carthage, and Rome. Pliny speaks of a mine opened by Hannibal, which supplied him with 300 lbs. of silver daily, and was worked by adits reaching a mile and a half into the mountain. This was at Guadalcanal, at the foot of the Sierra Morena, in the modern province of Seville. Pure silver, in its massive state, is the whitest of metals. It takes by burnishing a brilliant lustre, though inferior to that of its white alloys with copper. ”

“ Nothing has ever been invented that will prevent people from being crushed and trampled when they are crowding down a stairway. In all these respects, the great hall of the Cooper Union is admirable. It occupies space not otherwise valuable. ”

“ Ziervogel's method of extracting silver by roasting the sulphuretted ore to produce silver sulphate, leaching this with hot acidulated water, and precipitating with copper, is the simplest and cheapest of all; but it requires very skilful and delicate roasting, and ores comparatively free from lead, antimony, arsenic, and zinc. The three latter tend to cause volatilization of silver; the sulphide of antimony and lead cause a sintering of the roasting charge; copper dioxide, or too high a temperature in the furnace, leads to the formation of metallic silver, instead of the desired sulphate. ”

“ It would have been impossible for one head to carry the details of work and management, for one pair of eyes to superintend each part of the work, or for one pair of feet, however tireless, to travel all the ways which lead to and from a great modern industrial establishment. ”

“ The consumption of mercury in the Washoe process may be considered chiefly a mechanical loss, and only to a limited extent a chemical one. The pan amalgamation of slimes and refractory ores, with the addition of large proportions of copper sulphate and salt, involves a greater loss of mercury.—Refractory ores, not suitable for “raw” amalgamation by the Washoe or the patio process, are treated in many localities by the Freiberg process, consisting in the chlorination of the ore by roasting with salt, and its subsequent amalgamation. ”