124 Remarks 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- 
, 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 
eompelae chemical essay would doubtless sustain. 
* See the preceding account of the Moss and Busby mine. 
