372 Transactions.— Chemistry. 
gold, and likely to occur in the interior parts of our rocks, are ferrous sulphate 
of iron, organic matter, and metallic sulphides. These also reduce silver from 
certain of its solutions, but, as already noted, the difficulty is in finding a 
substance which will reduce these two metals simultaneously in coherent 
forms, and from such kinds of solutions as generally permeate our rocks. 
With this double duty to perform, and limited in this manner as regards nature 
of solvent, I cannot avoid thinking that but one of these reducing agents, 
the metallic sulphides, will be found equal to the occasion, The ferrous 
sulphate is thrown out at once from this service on account of its insolubility 
in such a menstruum, while organic matter appears to have a decided tendency 
to scatter the gold it reduces (see Art. LII), nor have we, as far as I am 
aware, produced any true alloy of gold and silver by their use. : 
I would not intend to convey the idea that such a mixed deposition is 
impossible, but only that, from what we at present know of this subject, the 
production of such an alloy by these means appears a very difficult undertaking. 
However, this particular question is, I understand, now being dealt with by 
Mr. Daintree, late assistant geologist to the Victorian Geological Survey,* so 
that the propriety or otherwise of retaining this theory of the origin of our 
auriferous deposits in their lodes by the interaction of organic matter may be 
left in abeyance until Mr. Daintree publishes. the results of his inquiry, as 
promised. 
I will therefore leave the question in this state, merely observing that 
should Mr, Daintree be unable to obtain the results he is in search of, I 
shall then claim for our metallic sulphides the sole duty of depositing at least 
that portion of our native gold which occurs in the reefs or fissures of our 
metamorphic rocks, 
Art. LII.—Critical Notes upon the Alleged Nuclear Action of Gold upon 
Gold reduced from Solution by Organic Matter. By W. Srey, Analyst 
to the Geological Survey of New Zealand. 
[Read before the Wellington Philosophical Society, 23rd October, 1872.] 
IS a paper upon the formation of gold nuggets which appeared in Part I., 
Vol. VIII., of the Transactions and Proceedings of the Royal Society of 
Victoria, the author, Mr. Œ. Wilkinson, states in reference to the question as 
to the origin of gold nuggets that “Mr. Daintree, formerly of our Geological 
Survey (that of Victoria) had on one occasion prepared for photographie use a 
solution of chloride of gold, leaving in it a small piece of metallic gold 
* « Athenzeum,” 22nd July, 1871. 
