Show A LITTLE OF everything exchanges copper can be precipitated from chloride solution with metallic iron malachite is the carbonate of copper the specific gravity of copper is gold and ana silver dissolve at nearly the same rate atom for atom in solutions containing equal proportions of potassium cyanide owing to the sulphuric acid andiron and iron it has been found that the use of water from mines is extremely injurious to boilers the min mill eral substances corrode and soon destroy them I 1 platinum has been found in the sands of f the yukon creeks but there is no record of the amount saved the account of the rich ness of those sands sand sin in platinum is doubtless exaggerated diamonds of fair size and considerable value have been found in butte and el dorado counties california but no systematic or con tinned effort to determine their source has been put in practice s an electric current cannot be sent through pure water but the addition of a minute quantity of other matter reduces its resist I 1 ance ordinary water admits of the passage of an electric current through it the various copper bearing mines of the pacific coast states furnish many gems for the cabinet such as splendid specimens of azurite velvet azurite large crystals of cuprite also of chrys ocolia covil lite and atac arnite A mill run of ore is ordinarily understood to mean a test of the value of a lot of ore large enough r to be run through a quartz mill it cannot in that sense be justly applied to a sample or small quantity A mill run deals with tons rather than pounds generally speaking it pays to sort ores going to mills where crushing is done on a large scale at low cost but where ores are shipped to custom mills and smelters shelters sm elters where transportation charges and treatment are high the reasons for careful sorting are obvious the value of mining machinery at present in south africa is conservatively stated av at much of it was made in this country and when the war permits the demand for repairs replacements etc will form a leading item in our exports of manu fractured articles |