338 A. LIVERSIDGE. 
Sonstadt’s second method was also tried, 7.¢., with barium 
chloride as follows :—‘ From half a litre to a litre of sea-water 
should be taken for the experiment. As much solution of pure 
chloride of barium is added to the water as will give a grain of 
precipitate. A day or two should be allowed for the precipitate 
to settle. The precipitate is collected, dried, mixed with borax 
and lead, and the button of lead obtained before the blowpipe on 
charcoal is cupelled. The bead obtained is yellowish-white, of the 
same colour as an alloy of sixty parts of gold to forty of silver, — 
or thereabout. For confirmation of the presence of gold the bead — 
may be dissolved in a very small test tube, in a few drops of aqua 
regia, which is then evaporated, at a gentle heat, nearly to dryness. 
A few drops of pure hydrochloric acid are added, and the solution 
again evaporated, to destroy the excess of nitric acid. The solu- 
tion is evaporated very nearly, but not quite, to dryness, a few 
drops of water are added, and the mixture warmed, and when the 
chloride of silver is settled, a drop of solution of stannous chloride — 
is allowed to fall down the side of the tube into the liquid, when | 
the characteristic gold reaction is obtained.” 
Sonstadt’s barium chloride method was tried on sea water from 
off Jervis Bay as well as from the coast at Coogee, but the yield 
of gold was either much less than by the ferrous sulphate method 
(see further on) or no gold at all was obtained, even when two % 
more litres were used. Similar results were obtained from the 
use of stannous chloride and mercuric chloride together. Mercurie ; 
chloride alone and afterwards precipitated by hydrogen cup 
gave fairly good results. It was thought that the prevmt 7 
addition of sulphurous acid, oxalic acid and other reducing sub- 
stances might increase the amount of gold obtained, but this was 
not found to be the case, on the contrary the yield was reduce : 
the 
As the result of a very large number of experiments with , 
film test upon gold chloride in distilled water and in sea-wale 
was found that :— 
it 
1, All the gold is not carried down by the film—not eve? oY : 
repeating the process and obtaining a second film ; 4 little gold : 
still being obtainable by a third film, 
i 
‘ 
es, 
‘ 
5 
