GEOLOGY. 323 



ores, 102 ounces of gold were lately reduced, being at the rate of 16 

 dwts. per ton, or twice the rate of the St. John del Hey ores. The 

 South of Scotland district had only been worked for its river deposits 

 in Clydesdale and Nithsdale, but in his (the lecturer's) opinion it ex- 

 tended throughout the lowlands. Gold was found in above forty 

 brooks or gullies, and all of the miners have gold for sale, obtained in 

 their holiday excursions. Mr. Cal vert mentioned that in the manuscripts 

 of Queen Elizabeth's time the diggers relied on keele, a reddish earth, 

 as an indication of gold, and the miners do now. He has seen it also 

 in Westmoreland, and had recognized it also in Australia and else- 

 where. At one place the miners, two years ago, got gold, which at 

 Glasgow they sold for 421. The Highland gold regions were unex- 

 amined. Gold localities had been reported in Aberdeenshire and 

 Sutherlandshire. The Wicklow divings were onlv shortlv referred 



* 



to. It appeared, by returns obtained from the Dublin goldsmiths, that 

 the present supply of the peasantry was about 2,000/. a year. In Uls- 

 ter the peasantry work the aura or gold mountains in Antrimshire ; 

 and the Mayola streams in Londonderry yielded gold. The yearly 

 produce of gold in these islands was now abont 5, GOO/, a year, which 

 might be largely increased. The number of gold bearing streams 

 known was one hundred. Gold had been found in nearly all the 

 clay-slate districts. Many of these were worked in the Middle Ages, 

 and probably also by the Romans. Gold, in ores, was found associa- 

 ted with silver, lead, copper, iron, and zinc ; with quartz, granite, 

 slate, oxide of iron, sulphate of iron. These ores have only been 

 worked of late in Devonshire and Merionethshire. The washing of 

 gold-stuff in our home districts was very rude, and not equal to that 

 in Australia, nor had there been for a long time any deep workings. 

 Many rich gold ores were thrown away, and much metal was pro- 

 duced from which the gold was not refined. The only two gold-fields 

 which had yet been worked had yielded considerable amounts. The 

 Lanarkshire district from a quarter of a million to half a million, the 

 Wicklow above 100,000/. The largest known nuggets were 3lb. from 

 Lanarkshire, and others of 2^ Ib. from there and Wicklow. Mr.Cal- 

 vert concluded by stating that he considered the clay-slate formations 

 of Canada would soon be discovered to be a vast gold-field. 



ON THE COMPARATIVE RICHNESS OF AURIFEROUS QUARTZ AT 

 DIFFERENT DEPTHS OF THE SAME VEIN. 



At the British Association, Dr. J. H. Blake stated that no shaft had 

 yet been made in California deep enough to test the correctness of the 

 opinion that auriferous lodes diminish in value as they descend, but he 

 described a circumstance which seemed to confirm that view. A hori- 

 zontal mass of auriferous quartz was discovered in Grass Valley, 

 which measured 60 yards by 45, and was from 6 to 18 inches thick ; 

 in the centre it was depressed 10 yards below the surface, its edges 

 cropping out all round. Every part' of this mass had been removed, 

 and was found to contain 1 oz. or 1^ oz. of gold to the ton ; one part 



