59 
of it is visible to the eye. Specimens of ore from various parts 
of the mine are shown, also specimens of the country rock. 
CASE 4, FRONT. — Gold ores of the Appalachian Mountains. 
These gold ores were the first exploited in the United States. 
They were nearly all abandoned at the time of the discovery of 
gold in California and have never regained their earlier im- 
portance. 
In the lower part of this case are gold and silver from Utah. 
CASE 3, REAR. — Gold ores, Mexico. They illustrate an 
unusual occurrence. Those from the Silver Reef consist of 
sandstone impregnated with argentite and ceragyrite. In one 
specimen these minerals may be seen replacing organic remains. 
CASE B. — Collection of nearly all the known alloys of gold 
and silver with copper, tin, zinc, lead, arsenic and other metals. 
Collection illustrating methods of saving gold and silver practiced 
by Tiffany & Co., New York. Here are shown wash water, 
concentrates from an exhaust blower that collects the dust of the 
shops, pieces of flooring of the shops, and shoes worn by work- 
men, and beside each of these are placed buttons of gold and 
silver obtained from articles of size similar to those shown. 
SILVER. 
CASE 5, FRONT.—Type specimens of silver-bearing miner- 
als. These are, in the order of their richness: native, or wire 
silver) argentite, 87 per cent, silver; cerargyrite, 75 per cent, 
silver; pyrargyrite, 65 per cent, silver; proustite, 65 per cent. 
silver ;stephanite, 68 per cent, silver. Galena and cerussite may 
also be regarded as ores of silver, for though they contain but 
small percentages of silver, they are so abundant as to consti* 
tute very important ores. With these should be mentioned, tetra- 
hedrite, which may contain as high as 17 per cent, of silver. 
There are a number of rare silver-bearing minerals. 
With each of these minerals is a tube containing the sub- 
stances of which the mineral is composed in the exact proportions 
in which they occur in the mineral itself. 
CASES 4, REAR, 5 REAR AND 6 REAR.— Silver ores^ 
Nevada. These include ores from the famous Comstock lode. 
