be
formed in reading the reports of assayists, through misconception of
the nature of the samples submitted for analysis. By way of example,
supposing that the residue left in the dish, or tray, after washing
down some eight pounds weight of crushed quartz, may not weigh more
than a quarter of an ounce. Of course this quarter of an ounce will
contain the gold washed out of the original eight pounds. Now the assay
report is usually given on the sample submitted; and is not of the
remotest use in forming a judgment on the value of a reef, or deposit,
unless the proporÂtion that the residue bears to the bulk is also
known. What would the Glenrock shareholders have underÂstood by the
assay of the sample brought home by me when told that it afforded 555
ounces to the ton ? The question here is per ton of what ? of quartz,
or of the sample ?
Now,
this particular sample may have been very thoroughly reduced, and its
auriferous character will entirely depend on the manner in which it has
been washed. In order to find the true quantity of gold in the quartz,
it will be necessary to divide the yield of gold afforded in the sample
by the proportion the sediment left bore to the entire quantity washed.
And the 555 ounces to the ton, then, shows the true quantity of gold to
the ton of quartz to be about eighteen pennyweights. Yet, assuming that
some gold had been lost in the washing, I next, in order to test the
accuracy of the first assay, submitted a
