124 RemarJcs on the Gold Mines of Virginia. 



mine. It may be regarded as affording as fair an approximation to 

 the real productiveness of the mine as can, at present, be obtained ; 

 for the ores were taken from every place in the hills where any dig- 

 gings had been made, and no allowance was admitted for waste in 

 washing. That this waste was of some moment, appears from the 

 fact, that on washing again the matter which had flowed from the 

 pans, a small portion of gold was, in every instance, obtained, even 

 when the washings were, again and again, repeated, on the success- 

 ive overflows of the pans. 



This fact, always observable in a greater or less degree, in the 

 washing of the gold, deserves to be particularly insisted on here. It 

 is certain that an important proportion of the very fine particles of 

 gold is usually lost in the washings. Those who are expert in this 

 manipulation find, that a fourth, and even a fifth or a sixth washing 

 will yield a valuable portion of fine gold. 



This occurs more generally in the pyritical ores in which the gold 

 is imbedded in excessively fine particles. This mass when reduced 

 to fine powder, gives a residuum of oxidized iron, (commonly called 

 black sand,) equal almost, in weight, to the fine gold, the latter being 

 malleable or flattened, while the former, being brittle, remains round- 

 ed or angular ; in washing this mixture in the pan, the gold gener- 

 ally remains on the upper side of the mass, and is therefore more 

 liable to be washed off by the slightest ripple of the water. On the 

 other hand, when the gold is imbedded in quartz ores, especially 

 those with fine fractures, called in Virginia sugar ore — more properly 

 granular quartz,* the gold being of a similar form, is more quickly 

 disengaged, and appears in larger grains. On the contrary, the fer- 

 ruginous grains or iron sand are so fine as to be scarcely visible, and 

 are invariably found at the bottom of the mass or residuum, and there- 

 fore, as well as on account of their greater weight, are much less 

 liable to be carried off by the ripple of the waters. In the purer 

 quartz ores, ordinary care in the use of the pan will recover, at the 

 first washing, a much greater proportion of the gold than in the other 

 case, where repeated and careful repetition of the washings will never 

 fail to give an additional yield. Hence arises the necessity of a dif- 

 ferent mode of operation upon the two kinds of ores ; a view which 

 a regular chemical essay would doubtless sustain. 



* See the preceding account of the Moss and Busby mine. 



