304 Proceedings of Lecvrned Societies. 



restrial substances, while the nebulae were evidently bodies of 

 gaseous vapour, the character of their light showing that there was 

 no solid body behind. 



Mr. F. 0. Calvert communicated A New Method of Extract- 

 ing Gold from Auriferous Quartz, so as to obviate the necessity 

 of employing mercury, which is both expensive and very deleterious. 

 Finding that gold, though but slowly acted on by a solution of 

 •chlorine, is readily dissolved by that agent as it is liberated from its 

 other combinations, or as in a nascent state, Mr. Calvert suggests 

 that the auriferous quartz should be acted on by hydrochlorine and 

 peroxide of manganese, when the gold is readily and completely 

 •dissolved, and is, after the separation of any copper that may be 

 present, afterwards precipitated in a metallic form by a solution of 

 protosulphate of iron (the green copperas of commerce). 



Mr. Spencer read a paper on Economising thr Sulphur Evolved 

 in Copper Melting. He described a furnace in which the sulphurous 

 fumes evolved during the calcining of the ores were conveyed into 

 the chambers employed for the manufacture of sulphuric acid ; he 

 estimated the loss of sulphur from the present wasteful and delete- 

 rious modes of calcining the ores as amounting to 70,000 tons per 

 annum, the money value of which would be upwards of £400,000. 



Dr. Machaltee furnished a paper on the Detection of Poisons 

 BY Dialysis — a probable application of this valuable discovery, 

 which was pointed out in the article on Dialysis in the 1st volume of 

 the Intellectual Observer, page 384, — in which he suggested that 

 the stomach or intestines of an animal suspected of having been 

 poisoned by any substance capable of being dialysed, might be made 

 to act as their own dialysers, by simply tying the openings so as to 

 securely enclose their contents, and then plunging them into a vessel 

 of water for some hours, when the crystalline poison, such as arsenic 

 or strychnine, would dialyse out, and could be readily detected in 

 the external fluid. 



Dr. Daubeny made some interesting remarks on the Decay of 

 Species, and on the Means of Extending their Duration. It was 

 assumed as a fact, that species (like individuals), both in the animal 

 and vegetable kingdom, wear out after a certain period ; but it was 

 suggested that there are natural contrivances whereby this inevit- 

 able termination was postponed to a later period than would other- 

 wise happen. The author suggested that one of these provisions 

 was the formation of new varieties, which diverged from the original 

 type, acquired great vigour, and so prolonged the existence of the 

 species from which they were derived ; consequently, plants propa- 

 gated by cuttings, which adhere to the same type as that one from 

 which they were immediately obtained, seemed to be more limited in 

 their duration than those produced from seeds. The production 

 by seed of plants which vary somewhat from the original type, is 

 more completely carried out when the pollen of one individual is 

 made to fertilize the embryo of another ; hence may arise the neces- 

 sity for these numerous and singular contrivances for preventing 

 self-fertilization which have been pointed out by Mr. E. Darwin 

 and others. The author mentioned, however, that eventually, even 



