ORIGIN OF GOLD NUGGETS. BYR 
Experiment 10, with molybdenite.—No gold was visible on the 
-molybdenite, but on closer examination some was seen between 
the cleavage planes of the mineral, and this under the microscope 
had a vermicular and matted structure. On removing the gold 
plate and cleaning with a brush, it was found to have increased 
0038 grammes in two months. 
Experiment 11, with mispickel.—The solution was decolourised 
in twenty-four hours, and this went on continuously for many 
successive days. Increase in weight in fifty-nine days -0006 gram. 
Experiment 12, with mispickel.—The gold foil was stained nearly 
black on both sides, over about two-thirds its area; the black 
deposit had a blistered or mammillated structure, very marked 
under the microscope, and readily felt with the finger nail. It - 
increased ‘0260 gramme in fifty-nine days. The gold on the 
mispickel was also dull and mammillated, but in part showed traces 
of cubes joined in strings, and in one place there were hexagonal 
plates (microscopic) of bright lustrous gold. 
Experiment 13, with mispickel.—The gold deposited on the 
mispickel was black and pulverulent, and without crystals. The 
gold on the gold foil was of a bronze-green tint. The plate 
increased ‘0089 gramme in weight in nine days. 
Experiment 14, with recent iron pyrites, Loffley’s, Taupo.—Con- 
tained a very large quantity of ferrous sulphate and sulphuric acid, 
probably none of the pyrites left unoxidised. It reduced a very 
large quantity of the gold solution, but none was permanently 
deposited on the plate, and its weight remained unchanged. On 
dissolving out with hydrochloric acid, a residue of spongy gold was 
left together with some particles of a white mineral, probably 
silica, as the springs at Loffley’s deposit this mineral. 
Hxperiment 15.—With cubical iron pyrites. Decolourised in 
twenty-four hours. The gold foil or plate was dull from the 
gold which had been deposited upon it. Increase in weight ‘0028 
gramme in fifty-nine days. | 
Expervment 16, with pyrites, Joshua’s Spa, Lake Taupo, N.Z.— 
Several charges of gold solution were reduced. The foil was 
