133 , 



hours ; other Mexican laborers twelve to fifteen dollars per month, 

 and to each man a ration of sixteen pounds of flour per week. 

 American laborers are paid from thirty to seventy dollars per month 

 and boarded. 



The cost of salt, wdiich is brought from near the coast, is four 

 cents per pound ; of copper twenty-five cents per pound, and wood 

 from four to six dollars per cord delivered at the furnace. The 

 .price of quicksilver is one dollar per pound. 



The first class ore was formerly smelted at the mine in Castilian 

 furnaces, with the addition of an ore of sulphide and carbonate of 

 lead, litharge and iron ore. The loss of silver was from fifteen to 

 twenty per cent., and the cost of extracting that metal about sixty 

 dollars per ton of ore. The yield, as before stated, was nearly one 

 thousand dollars to the ton. 



From the results obtained, in 1859, on one hundred and sixty tons 

 of amalgamated ore, it appears that about $24,000 worth of silver 

 was produced. The loss of quicksilver equalled one pound (=one 

 dollar) for every forty dollars of silver extracted. The consumption 

 of copper was 1480 pounds, of salt 32,000 pounds, and of wood 

 three hundred cords. 



The production of silver at the Heintzelman mine is estimated at 

 over '1100,000 (not including large amounts of ore stolen and worked 

 in Sonora) but had it been well and regularly worked and provided 

 with reduction works of sufficient capacity, it might have produced 

 over '$1,000,000 in the same time. 



This is the first experiment made in the United States in apply- 

 ing the barrel process to the treatment of argentiferous copper ores, 

 and it is not surprising that, in submitting to it ores of the peculiar 

 character which these possess, and especially when we consider the 

 absence of necessary facilities, we should find in it important defects, 

 many of which are remediable. 



No experiments have been made in working this ore by the patio 

 or Spanish-American amalgamation process, so that it is not known 

 to what extent the rejection of the present method would prove ad- 

 vantageous ; but the results obtained at Arivaca show conclusively 

 that, by remedying the defects within the limits of possibility, and 

 by proper substitution of mechanical for manual labor, the European 

 method can be used with profit in Arizona for ores of this class and 

 containing about one hundred and fifty dollars to the ton. 



The same may be said of the ores of many other mines which 

 are free from lead, and in which tetrahedrite or copper-glance is the 

 principal silver bearer. 



Near Arivaca there are said to be twenty-five openings on veins 

 worked formerly for gold and silver. 



The valley of this ranch is a large plain. The soil rests on clay 



