322 ANNUAL OF SCIENTIFIC DISCOVERY. 



massive, as is the case with those prepared in our laboratories ; but it 

 appears that the hydro-sulphuric acid, under certain conditions of tem- 

 perature and pressure, is a solvent of sulphurets, and a general agent of 

 crystallization. The properties of this acid explain the accumulation of 

 metallic sulphurets in the deep parts of mineral repositories, and of 

 metallic carbonates near their crop, or outgoings. Arsiuio sulphurets 

 and antimonio sulphurets were also formed. 



Conclusions. I had proposed to establish, upon experimental 

 proofs, the controverted, and, as I think, very probable opinion, 

 which attributes the filling up of the concretionary veins to incrusting 

 thermal depositions, and to show that the formation of a great number 

 of minerals which we there meet, whether they be crystallized or 

 amorphous, do not always pre-suppose conditions or agents far re- 

 ipoved from the actual existing causes. We thus, in fact, perceive that 

 the two principal elements of the most widely-extended thermal 

 springs, the sulphurets and the alkaline bi-carbonates, have sufficed to 

 produce twenty-nine distinct mineral species, almost all crystallized, 

 belonging to all the great families of the chemical compounds pecu- 

 liar to concretionary beds, each of which has some representatives in 

 my experiments. Means of synthesis equally simple, applicable how- 

 ever to compounds as variable, give certainly a great probability to 

 the speculative ideas which have directed me in these researches. It 

 will moreover be necessary to diversify them to a much greater extent, 

 and when we shall in the same manner have studied the different 

 chemical agents, and the influences of every kind which can modify 

 their effects, we shall undoubtedly succeed in defining the probable 

 condition of the formation peculiar to each class of metalliferous beds ; 

 and in tracing their origin step by step, in the same order of systematic 

 experiments, we may finally arrive at the crystallized rocks which 

 associate themselves to these beds by methods and phenomena of 

 continuity which it is impossible to mistake. 



OX THE PRODUCTION OF GOLD IN THE BRITISH ISLANDS. 



In a communication on the above subject presented to the British 

 Association, by Mr. J. Calvert, it was stated that gold was found in 

 forty counties in these islands, and over an area of 50,000 square 

 miles. He thus classified the gold regions : The West of England, 

 North Welsh, Mid-England, Northumbrian, Lowland, Highland, Ulster, 

 and Leinster. In Cornwall, the tin-streams, which were of the same 

 composition as gold diggings, had long been known to contain nuggets 

 and coarse dust, or hops of gold, but had only been slightly worked 

 by Sir Christopher Hawkins, at Ladoch. The largest Cornish nugget 

 was not worth more than about ten guineas. The Cornish districts 

 were very rich in gold. The Dartmoor district contained gold in its 

 northern and southern streams. A miner, named Wellington, got 

 about 40/. worth of gold, at Sheepston, and Mr. Calvert had obtained 

 gold from the granite by this process. In the West Somerset were 

 four companies for working gold ores. From 55 tons of Poltimore 



