‘ORIGIN OF GOLD NUGGETS. © 321 
Experiments 2 and 3—A plate of pure gold was used as a 
nucleus in each case, and the solution was exposed to the air as 
above ; one plate lost ‘0042 and the other -0038 gramme. 
Experiment 4, with cork.—The gold solution was left in a 
stoppered cylinder with a slice of clean new cork until the yellow 
colour of the solution had disappeared, showing that all the gold 
had been removed from it. Some gold was precipitated at the 
bottom of the cylinder, some on the sides, and a little floated 
as films on the top, there was also a small quantity of gold precipi- 
tated on the gold plate, but this was non-adherent and came away 
on washing the plate in a jet of water. This plate underwent no 
change in weight. 
Note.—All of my experiments were carried out in full daylight, 
and not in the dark like those by Wilkinson, Egleston, and others. 
Experiment 5, with Swedish filter paper.—The yellow colour 
soon disappeared from the solution, and the paper acquired a 
purple colour. The gold plate lost 0036 gramme in weight. 
Experiment 6, with phosphorus in ether.—The solution soon 
became colourless, and a black precipitate of gold was thrown 
down, on the bottom of the cylinder and on the gold plate. Float-. 
ing films of gold also formed on the surface. On washing the 
gold plate with a jet of water all the gold deposited on it was 
washed away, and on drying and weighing it was found to have. 
lost ‘0004 gramme. 
Haperiment 7—In this case a freshly broken jagged fragment. 
of gold in quartz was used as the nucleus instead of a gold plate, 
but cleaned with the same care. Cuttings from a cedar pencil. 
and some scraps of paper were added, these acted in the same 
way as the cork and were ‘mineralized ” by the reduced gold ;. 
the gold and quartz nucleus lost (0021 grammes in weight. 
EHaperrment 8—Paper and wood were used as in experiment 7, 
with a nucleus of jagged gold set free from quartz by means of | 
hydrofluoric acid ; the nucleus lost ‘(0013 gramme. 
U—Sept. 6, 1893. 
