In dry assays the metal is almost always separated and weighed as metal; in wet gravimetric assays the metal is more usually weighed in the
The methods of assaying are best classed under two heads, Gravimetric and Volumetric, in the former of which the final results are weighed, whilst in
Acetic Acid, HAc or C2H4O2. (sp. gr. 1.044, containing 33 per cent, real acid).—An organic acid, forming a class of salts, acetates, which are for
Weighing.—The system of weights and measures which we have adopted is the French or metric system; in this the gram (15-43 grains) is the unit
Silver is widely diffused, and has been found in most mining districts. It occurs native in sufficient quantity to constitute one of the chief ores
The relation of the weight of a substance to its volume should be kept in mind in all cases where both weight and volume are
Mercury occurs native and, occasionally, alloyed with gold or silver in natural amalgams; but its chief ore is the sulphide, cinnabar. It is comparatively rare,
Gold occurs in nature chiefly as metal. It always contains more or less silver, and, in alluvial sands, may be associated with platinum and iridium. Gold
Copper occurs native in large quantities, especially in the Lake Superior district ; in this state it is generally pure. More frequently it is found
This section of the Paper deals with the abrasive character of rocks affecting crushing machinery. The investigation has followed two courses, firstly, an analysis of