GOLD AND SILVER IN SEA-WATER. oor 
The sea-water first examined was collected from the coast at 
Coogee, away from any fresh water or other drainage. Eleven 
trials of this water were made with 200 cc. as recommended by 
Sonstadt, but no trace of a purple or even pink tint was obtained; 
but, with 600 cc. a faint amethyst tint was obtained after stand- 
ing some time. As a rule, after adding the stannous chloride, a 
white or grey precipitate came down in the course of a few days, 
and this precipitate in many cases became pink, purple or slate 
coloured. 
To check Sonstadt’s method, various experiments were carried 
out. Gold chloride (from pure metal dissolved in chlorine water) 
was added to Coogee sea-water in the proportion of one grain of 
gold to the ton, and 200 cc. of this was treated by Sonstadt’s 
process on March 19th, 1895, when a light brown precipitate was 
thrown down by the stannous chloride; on the 27th the precipitate 
was of a red colour below with a pale pink layer above; on the 
3rd April the pink tint was more decided. Hence if allowed to 
stand for a few days, the test will detect in 200 cc. the presence 
of added gold in the proportion of one grain to the ton of sea- 
water, the gold originally present only being recognisable in 600ce. 
On December 11th, 1894, a litre of the Coogee sea-water was 
oncentrated and the test applied, no trace of pink or purple | 
*ppeared, but on February 8th, 1895, a slight brown sediment 
had formed, which may have been due to gold. 
Next two litres were treated on December 28th, 1894, and 
allowed to stand until February 8th, 1895, when a faint pink tint 
was observable on the surface of the white precipitate. The second 
chlorine water extract of the film yielded a white precipitate which 
also had acquired a pink tint on February 8th. 
On August 14th, 1895, two more samples each of two litres of 
ee water were tested. On the 15th the precipitates were 
brownish, the brownish tint seems to be due to the presence of 
gold. The contents of the two test tubes were mixed together, 
dried and scorified with’ 250 grains of assay lead free from gold, 
when a small bead of gold was obtained. 
V—Oct. 2, 1895, 
