16 The Extraction of Gold. 
the total gold contents of the quartz, or at the lowest calcu- 
lation £1,000,000 per annum. I doubt if any works are 
sustaining less than twenty-five per cent. loss, and several 
instances have come under my notice where there was a 
large per centage of sulphides in the quartz, and the loss of 
gold was in consequence from fifty to seventy per cent. of 
the total contents. The discovery of any method that would 
retain a fair proportion of the gold now lost, would add 
materially to the prosperity of the mining interest, but the 
direct saving is not all the benefit that would be obtained 
from it. Numerous quartz veins, now considered too poor 
to remunerate the miner for working them, would yield a 
fair profit if the gold in the sulphides were made available, as 
well as the free gold in the quartz, and the advantage 
derived from this source would be nearly as great as that 
accruing from the direct saving. or. 
It has been commonly asserted that this colony was far 
behind other mining countries in the adaptation of improved 
methods for extracting the gold; but, judging from the 
most reliable returns we can obtain, this certainly is not the 
case, and either as regards the character of our machinery, 
or the attention given to improved methods of treating the 
ore, we have no reason to be ashamed of the position we 
hold. It should not be matter for surprise that it has taken 
us fifteen years to solve the problem which has baffled other 
gold miners for four times that period, with all the resources 
of an old country, cheap labour, and cheap material at their 
command. 
For convenience the gold found in mineral veins may be 
divided into two classes: first, the free gold, meaning that. 
deposited in the quartz, slate, or other matrix in a form 
rendering it capable of liberation by the ordinary process of 
crushing; and, second, the pyritous gold, meaning that 
deposited with and enveloped by the sulphides of iron, 
copper, antimony, and lead, but principally in this colony 
with iron. , 
The greater part of the free gold is deposited in particles 
large enough to be liberated and retained by the ordinary 
reducing process, but in nearly all gold-bearing quartz a 
certain amount of fine gold exists, which cannot be retained 
by the usual mode of treatment, and in some few exceptional 
‘cases the proportion of this fine gold is so considerable as to 
form one-third of thegold lost. This fine gold, when seen in the 
quartz with the aid of the microscope, presents the appearance of 
