204 Value of Native Gold, ce. 
standing at 80 inches, will weigh 1000 ounces; and this is 
taken as the specific gravity of water. ‘ables of specific 
gravities are given for a variety of other substances, and 
these tabular values are, in point of fact, the actual weights 
of a cubic foot of each: for instance, the specific gravity 
of pure Gold cast is 19258 ; of pure Gold hammered, or 
laminated, 19861. In point of fact, these numbers repre- 
sent in each case the weight in ounces of a cubic foot of 
this material; the greater weight of the hammered Gold 
being due, as may be easily imagined, to the compression 
of the particles, a greater number having been crowded into 
the same space. 
Gold, with the exception of platina, is the heaviest metal 
with which we. are acquainted: any admixture or alloy of 
the Gold with other metals will diminish its specific gravity, 
and, as a matter of course, its value in some proportion 
to the quantity, weight, and value of the metal with 
which it is combined ;—for instance, Standard Gold, as it is 
called, that is, the Gold of which the circulating medium 
in England is composed, contains 2 parts of copper in 24; 
and the admixture of this proportion of copper, a metal 
whose specific gravity is 8878, reduces the specific gravity 
of Standard Gold to 17486, if cast; and to 17589, if ham- 
mered, or laminated, as it is when in coin. 
These are facts which have been carefully examined and 
recorded, and they afford the principal elements which are 
required in discussing the subject, affording a standard of 
comparison not only as regards the specific gravity of 
metallic compounds, but as regards the exchangeable value 
of the precious metal. 
In carrying out a series of experiments as to the specific 
gravities of various metallic compounds, my first object was 
to ascertain the degree of confidence which I could place on 
