336 A, LIVERSIDGE. 
these for me, found both gold and silver, but not in larger pro- 
portion than usual.” 
The results were, per ton :— 
Copper Sheathing. Muntz Metal. 
oz. dwt. grs. oz. dwt. grs. 
LO Baas 3 eae ame 9 | U °°. ie 
Silver £439 5 S28 
Professor Judd, ¥.R.s., informed me that a paper upon this 
subject was published in a Norwegian journal by Miinster, about 
1891, but I can find no reference to it in our Sydney libraries. 
Sonstadt, in his paper on the presence of gold in sea-water gives 
various methods for the detection of the gold, and in a later letter 
to the Chemical News, March 11th, 1892, refers to his previous 
communication of 1872, and states that the amount of gold is 
“far less than one grain per ton.” 
His first process is as follows :—Two or three decigrammes of 
pure ferrous sulphate are dissolved in the water, which is acidu- 
lated by two or three drops of hydrochloric acid. The solution is 
heated in a chemically clean well glazed porcelain dish, over # 
small flame, so managed that the flame may touch the under part 
of the dish without causing ebullition. Under these circumstances 
a lustrous film of iron oxide forms in the dish, commencing from 
tho portion directly heated by the flame. The heat is continued, 
without boiling, until the sea-water is evaporated to about half, 
or so long as the film increases in extent and in lustre. The 
liquid is then poured off, the strongly adherent film is rinsed with 
a little water ; and then about 50 cc. of strong chlorine water 18 
allowed to stand i in the dish for an hour or two, after which it is 
slowly evaporated down (over the film) to a few drops, # drop 
dilute hydrochloric acid being added towards the end of the 
evaporation. The liquid, which should be nearly colourless, - 
then poured into a test-glass containing a few drops of solution’ 
stannous chloride, when, after a few minutes, the liquid takes # 
bluish or purplish tint, which may be exactly matched by a drop 
or two ofa suitably diluted solution of gold added to 4 corre 
ponding portion of tin-salt in another glass.” 
