Chemistry. 181 



Observations on some Mines of the United States. By Dr Charles T, 

 Jackson. — A long band of iron and copper pyrites exists in the State of 

 Vermont, which has been long worked for the manufacture of green vitriol. 

 In the districts of Vershire and Corinth, it becomes so rich in copper, as 

 to contain on the average, 16 per cent, of that metal. Dr Jackson has 

 examined the conditions under which the copper is met with. It occurs in 

 a series of parallel veins situated between beds of mica slate, the direction 

 of which is nearly north and south, and the inclination of which is about 

 30°. The mean thickness of the veins is from three to four feet. The 

 pyrites contains a notable proportion of gold, though not in sufficiently 

 large quantity to permit its separation at the cost of the copper. Dr 

 Jackson proposes to obtain it by roasting with a quantity of nitrate of 

 soda, lixiviating the sulphate of copper, and extracting the gold from the 

 residue by amalgamation. 



The most interesting mine in Vermont is that of Bridgewater, situated 

 about five miles from the village of that name. The veins, whith are 

 numerous, are quartzose, and contain gold, argentiferous galena, blende, 

 and copper pyrites. The neighbouring rocks are taicose and chlorite 

 slates, formed of granular quartz, with talc and chlorite in crystalline 

 scales. The beds run from north-east to south-west, while the veins of 

 auriferous quartz run nearly north and south. On examining the quartz 

 veins , where they are cut by the stream which passes through the valley, 

 numerous particles of gold were found. Blende and galena are the prin- 

 cipal minerals of the vein ; and on pulverizing and washing different speci- 

 mens, there was always obtained a large quantity of galena mixed with 

 gold, which can be separated without the use of mercury. The whole gold 

 passes into the lead, and can be readily separated by cupellation. A ton 

 of the lead gave in this way, gold to the value of 603 dollars, and 25 dol- 

 lars of silver. It is remarkable that all the accessory minerals of the 

 veins contain gold, and it is present in the gahnite and blende, which are 

 found in them. 



The mines of Georgia and North Carolina, are at present in active work, 

 and their production is rapidly on the increase. The Goldhill mine in 

 North Carolina produces weekly gold to the value of 3000 dollars. 



CHEMISTRY. 



Researches upon the Ethers. By M. Berthelot. — M. Berthelot has 

 studied the action exercised by the acids in sealed tubes with the aid of 

 time and heat, upon the compound ethers, common ether, and alcohol. 

 This action, in certain cases, results in known phenomena, in others it 

 has given some new results, which are not without some interest, relative 

 to the constitution of ethers. 



They belong to three different classes — 



1st, The formation of compound ethers by means of common ether and 

 acids. 



2d. The direct formation of ethers by means of alcohol and acids. 



3d. Decomposition of ethers under the influence of water and acids. 



1. Formation of compound ethers by means of common ether and acids. 



M. Berthelot obtained benzoic ether, by exposing benzoic acid and 

 ether in a sealed tube to a temperature of 360° C. for nine hours ; the com- 

 pound thus obtained had the odour and all the properties of benzoic ether; 

 it boiled at 210° C. The formation of this ether commenced at 300° C, 

 but at this temperature even after prolonged contact very little was 

 formed. 



Ether and palmitic acid produce by heating for nine hours at 360° C. ; 

 palmitic ether, fusible at 22° C. 



Ether and butyric acid at 360° C. in six hours produce butyric ether. 



