GOLD AND SILVER IN SEA-WATER. 349 
tion nearly always showed a loss, and sometimes a very consider- 
able one. 
All the above evidence is in favour of gold being present in sea- 
water off the New South Wales coast in the proportion of about 
‘D to 1 grain per ton, or in round numbers from 130 to 260 tons 
of gold per cubic mile. This of course means an enormous 
amount for the whole of the ocean, the cubic contents of which 
used to be put down at 400,000,000 cubic miles, and if the gold 
be uniformly present at the rate of 1 grain per ton the total 
amount would be over 100,000,000,000 tons of gold; a later 
estimate is 308,710,679 cubic miles, this even would mean over 
75,000,000,000 tons of gold. But at the present day it would 
‘probably not pay to extract the gold by itself, although it might 
asa bye product in the manufacture of salt, bromine, &c. The 
fnormous amount of gold in the sea is, however, probably very 
small in comparison with the amount scattered through sedi- 
mentary and crystallised rocks, i.e., apart from gold in veins and 
other deposits, 
SILveR IN Sea-WATER. 
All the sea waters gave some silver, usually from one to two 
grains per ton, but I consider the scorification and cupellation 
Process lacking in the necessary precision for the exact determin- 
ation of silver in such minute quantities as it exists in sea-water, 
I have therefore omitted all the determinations of silver from 
this paper, but I may publish them later on with the results of 
other experiments now in hand. 
Malaguti estimated the amount of silver in sea-water at 001 
sramme per 100 kilos of sea-water, or at only ‘15 grains per ton; 
- Thave quoted him more fully in the next paper in this volume 
the removal of Gold and Silver from Sea-water by Muntz 
Metal Sheathing.” 
