Value of Native Gold, éc. 203 
more specifically hereafter. Before I enter into the detail 
of these experiments, it may be desirable that I should give 
some brief explanation of the different forms under which 
the Gold generally presents itself. Gold is found in all 
cases in a metallic form, or, as it is called, native Gold. 
In this state, however, it is by no means pure, being gene- 
rally combined chemically with some other metals, as platina, 
silver, copper, &c. 
In many instances it is brought to market in lumps, or 
“nuggets” as they are called, which contain, besides the Gold 
alloyed with some metal, portions of quartz or other extra- 
neous material, forming the matrix in which the Gold was 
originally deposited, or with which it had become combined 
_ accidentally. In other cases it is brought to market in dust, 
or grains of a greater or less degree of fineness, the product 
of the washing of the earthy strata in which the Gold had 
been deposited, this dust of course containing more or less 
extraneous matter, in proportion to the care with which the 
washing had been conducted, and consisting very com- 
monly of iron ore, sand, earth, particles of quartz, &c. 
The object of the experiments which I am now about to 
lay before the Society was to discover the quantity of the 
alloy combined with the native Gold, in the first place ; and, 
having established this, to ascertain the amount of the extra- 
neous matter either in the lumps or the dust. Should I be 
able to show that this can be done with facility, I shall 
have done something towards establishing a standard by 
which the dealers in Gold may regulate their transactions. 
Now, every material whose structure is definite has a given 
specific gravity; that is, a given bulk of such material will 
weigh a certain number of ounces or grains. The standard 
of comparison in all cases is water: a cubic foot of distilled 
water, at a temperature of 60° of Fahrenheit, the barometer 
S2 
