W. Skey. — Formation of Gold Nuggets in Drift. 379 



stadt's experiments on tlie other hand are detailed minutely, and his state- 

 ments are supported by the results of different processes. 



The amount of gold present in the water taken from Ramsey Bay, he 

 states to be very minute, " less than one grain in the ton," still the fact of its 

 presence at all in such water is exceedingly interesting as showing an escape 

 of gold from the land seaward, and so confirms^ the correctness of the various 

 allegations I have referred to respecting the auriferous character of certain 

 of our springs and mine waters. 



Thus in different ways the first question involved in this theory of Mr. 

 Selwyn is answered in a most satisfactory manner. 



As to the means by which the gold present in these waters has been 

 reduced therefrom and aggregated in masses, solid, homogeneous, and occa- 

 sionally of considerable size, we have no lack of substances certain to be 

 present in these drifts, and capable of effecting the reduction of gold and 

 silver from the kind of solutions likely to be present there. In various kinds 

 of organic matter and in sulphate of iron we have substances which will effect 

 this with facility, but we have no sure evidence as yet to show that either of 

 these substances will aggregate the gold, which they reduce or locate in a 

 marked manner, or preferentially, upon the gold already reduced. 



That gold will be reduced by these substances is certain, but all our 

 present experience in regard to the deposition of gold by them shows that 

 gold so reduced will be dispersed rather than aggregated, so that it would 

 appear that nuggets of gold could not well be formed in this manner. 



In our mineral sulphurets, however, we have agents which are not only 

 capable of reducing gold and silver from solution, but besides are capable of 

 locating them when so reduced in coherent and bulky masses. 



I may state that their nuclear action upon gold depositing from solution 

 by aid of organic matter was suggested by Mr. Charles Wilkinson,* while 

 their competency to reduce the gold from solution without addition of 

 organic matter was shown by me in Vol. III. of our Transactions, pp. 227— 

 230; thus the aggregation of the nuggetty forms of gold from solution becomes 

 a still more simple matter, only one reagent being necessary, so that there is a 

 greater probability of such depositions obtaining than were a double process 

 necessary. 



Knowing the action of sulphides, the manner of the mode of formation 

 of a portion at least of these nuggets seems apparent. Conceive a stream 

 or river fed by springs rising in a country intersected by auriferous reefs, 

 and consequently in this case carrying gold in solution ; the drift of such a 

 country must be to a greater or lesser extent pyritous, so that the debris 

 forming the beds of these streams or rivers will certainly contain nodules of 

 * "Trans. Roy. Soc. Vict.," Vol. VIII., Art. II. 



