COLLECTIONS IN ECONOMIC GEOLOGY AND METALLURGY. 29 



From the settler the pulp passes through two agitators 9 feet in 

 diameter aud 4 feet high, running at eleven revolutions per minute, 

 lu these a small amount of amalgam that has been carried away 

 mechanically during the washing is saved ; from the agitators the 

 pulp passes to the tailings dump. 



The amalgam is taken from the settlers, cleaned and retorted. The 

 retorts hold about 200 pounds of amalgam, and it requires about 8 

 hours to distill the mercury. The bullion from the retort is melted and 

 cast into bars weighing about 100 pounds, eight bars per day being the 

 products of the works. The bullion is from 600 to 800 fine. 



The collection was made by the writer with the assistance of Mr. J. 

 E. Gallagher, the superintendent of the mill, in September, 1884, and 

 includes five samples of the lump ore, a sample of the material pass- 

 ing through the grizzly, aud a sample of the ore from the rock crusher, 

 the dried and stamped ore, the dried and stamped salt, the mixed ore 

 and salt, a full series of roasted ore and flue dusts, the mercury and 

 amalgam, the bullion and a model ingot. The exterior of the mill is 

 shown in PL. v. 



STAMP MILL SAMPLES. 

 Ore. 



(1) Quartz, stained by decoaipositiou products, sliowiug especially manganese and 

 a little copper. (11476.) 



(2) Decomposition products, containing lead salts, showing stains of copper and 

 manganese. (5573l<!.) 



(3) Decomposition products aud quartz, showing slight staius of copper and man- 

 ganese. (55696. ) 



(4) Galena and blende, in chert. (55697.) 



(5) Galena, containing ruby silver. (55695.) 



(6) An average sample of what passes through the grizzlies. (.55700.) 



(7) Crushed, as it comes from the breaker. (.55701.) 



(8) Dried, after passing through the hot cylinders. (55702.) 



(9) Stamped. (55703.) 



Salt. 



(1) Used for chloridiziug, obtaiued by solar evaporation of the water of Great Salt 

 Lake, Utah. (55704.) 



(2) Dried aud stamped, ready for mixing with the ore. (.55705). 



Furnace charge. 



(1) Ore carrying 105 ouncesof silver, mixed with 17 per cent, of salt, ready for charg- 

 ing into the Stetefeldt furnace. (55706.) 



F UltyA VE SA MPL ES. 



Uoasted ore. 



(1) From main stack of Stetefeldt furnace. (5.5707.) 

 (•J) From return line of Stetefeldt furnace. (55708.) 



