BRITISH ASSOCIATION MEETING. 



515 



ounces of gold from two hundred and twelve tons of auriferous mineral, being 

 at the rate of about six and a-half ounces to the ton ! 



The author believes this to be the first public record of a hundred weight of 

 gold having been obtained from the Crown Lands of this country, the value of 

 which is about five thousand three hundred pounds. 



This " Royal Mine" pays a royalty of one-twelfth to the Crown. The cost 

 of gold-extraction has been very inconsiderable, and there is a probability of a 

 continuance of a yield of gold at the present rate for some time to come. 



Seven years ago, the author determined, unwisely, perhaps, never to leave 

 this vexed question until he had mastered it. He has done so. Experiments 

 are ended. It is proved, what many then doubted, and many more derided, 

 that gold does really exist in the Dolgelly district, and that it can be extracted 

 from the minerals in remunerative quantity. He was glad to have had the 

 opportunity of making this statement before the Geological Section of the 

 British Association for the Advancement of Science. 



At the conclusion of the paper, Mr. J. Beete Jukes, P.R.S , P.G.S., Director 

 of the Geological Survey of Ireland, said the existence of gold in North "Wales 

 hncl long been known, but it was not in sufficient quantities to render its pro- 

 duction remunerative. 



A discussion ensued between Professor Smith, of Sydney, Australia, and 

 Mr. Readwin, upon the modes of extracting gold from its matrix ; Mr. Read- 

 win stating that, at the Clogau mine, particularly referred to in his paper, the 

 gold was extracted, at present, chiefly by a process of amalgamation. 



Professor Smith inquired whether some of the mercury was not lost in the 

 process ? To which Mr. Readwin replied that some of the mercury was always 

 lost ; it became so finely divided that some of it was sure to be carried away. 



Mr. Smith said he perceived that in old North Wales they were falling into 

 the same difficulty as their friends in New South Wales. There were many 

 things which would have a singular action upon mercury, and likely to injure 

 its effect on the gold. The action they had was a chemical one, and therefore 

 the gold producers of New South Wales had depended to a great extent upon 

 mechanical action exclusively, and generally they had been very successful. 

 If anyone could point out any means by which gold could be satisfactorily 

 separated from the quartz it would be a great boon. The mechanical means 

 they employed in New South Wales would leave only half an ounce per ton, 

 which was considered very fair. The production of gold in Old North Wales, 

 as detailed by Mr. Readwin, surprised him very much. The yield of gold in 

 Yictoria or New South Wales did not exceed one ounce per ton of quartz, and 

 in many instances half an ounce was considered a fair yield. The digger of 

 Australia would be extremely proud to get it in such quantities as six ounces 

 per ton, as Mr. Readwin had stated the yield of the Dolgelly quartz to be. 

 Prom three to four ounces per ton would be considered very good anywhere 

 in the gold districts of Australia. In some small localities the yield had been 

 as high as thirty ounces, forty ounces, or. even more, per ton, but they were 

 exceptional, and did not last long. 



Mr. Readwin remarked that there was this difference : in the one case the 

 gold was obtained ; in the other, not. There was no difiiculty about it. By 

 the process of amalgamation care should, of course, be taken not to intrude 

 any mineral that would have the effect of neutralizing the affinity of mercury 

 for gold. In reply to the last observation of Professor Smith, Mr. Readwin 

 said he believed that the same law of produce obtained with respect to gold as 

 with other metals. In the case referred to it certainly appeared to be so. 



In answer to another question, Mr. Readwin stated that the actual cost of 

 obtaining the one thousand three hundred ounces of gold was, he should think, 

 not more than three hundred pounds. 



