r86 NEW YORK STATE MUSEUM 



Sands from many localities in this section of the state liave been 

 tested by the " Sutphen " process, and nearly all samples have 

 shown some values of gold when treated by this method, which can 

 not be obtained by the standard fire assay. 



The fire assay is the method at present employed for deteraiining 

 the actual quantity of gold that an ore contains. To make this test, 

 a portion of ore is accurately weighed, mixed with the proper fluxes 

 to aid the heat in breaking down the chemical composition of the 

 rock, placed in a crucible, and submitted to a heat sufficient thor- 

 oughly to fuse the mass. The gold, being heavier than the rock, 

 sinks through the molten mass, and is collected in pure lead at the 

 bottom of the crucible. The button of lead and gold thus formed, 

 is then freed from the mass and cupelled, l)y which process the 

 lead is oxidized off, and the gold is left in the form of a spongy 

 mass, the weight of which, compared to the weight of ore used, 

 sbows the percentage of gold contained in the ore. The propor- 

 tion is usually expressed by the value of gold contained in one ton 

 of ore. This process is so perfect that no commercial method of 

 treating ore has yet been devised which will extract all the gold that 

 the tire assay shows to be present in the ore. The fire assay will 

 separate the gold from an ore that contains only 20c worth a ton. 

 The sand at Hadley is said to show about §7.50 worth of gold a ton 

 when treated by the Sutphen process. It is said that this gold is 

 thought to exist as a bromid. Bromin is an extremely volatile ele- 

 ment, and there is no visible reason why its chemical combination 

 with the gold should not be readily broken down by the heat of the 

 fire assay, and the gold obtained as usual. 



A sample of sand collected from the spot from which the mill's 

 supply is obtained was assaj^ed for the museum, and the value was 

 reported to be a " trace " of gold to the ton, which means a value 

 of less than 20c a ton. Xo value of silver was obtained. Another 

 sample of the same sand was tested by Dr E. J. "Wheeler, of 

 Albany, for the presence of bromin, but no trace of this element 

 was detected. These two tests prove that the Hadley sand does not 

 contain bromid of gold to the value of $7.50 a ton. In just what 

 chemical combination or physical condition the gold could exist in 

 the sand to the value of 87.50 a ton, and would not be detected by 

 tbe fire assay, but, after undergoing a simple chemical operation, 



