328 A. LIVERSIDGE. 
Experiment 39, with sand, from April 26 to June 1.—Although 
one charge of two ounces of the gold chloride was decolourised 
and another about half decolourised, the plate underwent no 
change in weight. The solution was doubtless reduced by organic 
matter present in the sand. 
Experiment 40, with gravel, from Bingera Diamond Mines.— 
Solution not decolourised, but the plate lost -0008 g. in fifty- 
nine days. 
EHaperiment 41, with wash dirt, Inverell, N.S. Wales.—Minute 
flakes of bright gold were found intermingled with the clay from 
this dirt. Foil increased :0003 g. Decolourised two charges, 
4.e., four ounces of the solution. 
Experiment 42, with granite, Hartley, N.S.W.—Foil became 
dull and stained on one side, and had increased -0006 g.in weight 
in fifty-nine days. 
Experiment 43, with granite, Hartley, N.S.W.—The powder of 
this granite turned brown like a pale clay ; the foil became dull, 
much stained, and increased ‘0002 g. in weight in fifty-nine days. 
Experiment 44, with white quartz.—Decolourised two ounces 
of the solution, and a second two ounces partly ; increase in gold 
plate, -0002 g. in fifty-nine days. 
Experiment 45, with clay, University Paddock.—Decolourised 
several charges. Foil became dull, and increased -0019 g. in 
weight in fifty-nine days. 
Experiment 46, with statuary marble.—This decolourised two 
ounces of the solution before the addition of the gold plate and 
several successive charges after; the plate darkened in colour and 
increased ‘0002 g. On dissolving the marble in hydrochloric acid 
a residue of brown mammillated gold was left. 
Experiment 47, with apatite, Canada.—As the solution was not 
decolourised after twohundred days, the gold foil was not reweighed. 
Experiment 48, with serpentine, containing a little magnetite. — 
Decolourised four ounces of gold solution, but the plate only 
showed an increase of ‘0001 g. in fifty nine days. 
* 
