110 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Berlin before the Emperor of Germany and his court, and ex- 

 cited much admiration. 3 A, August 10, 1872, 96. 



ACTION AT EED HEAT OF CHAECOAL AND 1E0N ON CAEBONIC 



ACID. 



Professor Dumas, in summing up the result of an investiga- 

 tion into the action exercised at a red heat by charcoal and 

 iron upon carbonic acid, remarks that we may consider as es- 

 tablished, first, that absolutely dry carbonic acid, in passing 

 over charcoal entirely freed from hydrogen, is converted, at a 

 dull, cherry-red heat, into oxide of carbon; second, that if the 

 charcoal is in excess, the carbonic acid disappears entirely, re- 

 placed by perfectly pure oxide of carbon ; third, that wood 

 charcoal, heated most energetically, retains some hydrogen or 

 water, which it loses only under the prolonged influence of 

 chlorine at a red heat ; fourth, that charcoal which has not 

 undergone treatment by chlorine, being employed to convert 

 the carbonic acid into oxide of carbon, always furnishes a 

 gas, accompanied by some traces of hydrogen ; fifth, that a 

 slow current of dry carbonic acid is partly converted by iron, 

 heated to a dull, cherry red, into oxide of carbon, a consider- 

 able proportion of the carbonic acid always remaining unal- 

 tered, or becoming regenerated. 6 .2?, August 26, 1872, 519. 



PEODUCTION OF CEETAIN METALS IN 1866. 



A few interesting facts in regard to the production of some 

 of the less extensively used metals have come to light through 

 the Paris Exposition of 1867. The yearly product of arsenic 

 was 5210 centners (each 110 pounds nearly) of which En- 

 gland produced 2230 ; Austria, 250 ; Prussia, 2450 ; Saxony, 

 280 or about 286 tons. The yearly production of mercury 

 was 64,392 centners of which California produced 36,000 ; 

 Spain, 22,000; Peru, 3200 ; Germany and France, 2600 ; Italy, 

 592 or about 3541 tons. The yearly production of antimony 

 was 8370 centners of which England produced 4000; Aus- 

 tria, 1600; France, 1100; Northern Germany, 1300; Italy, 

 200 ; Spain, 170 or about 460 tons. 



A singular point in the above statement is the large amount 

 of arsenic that is consumed. It is well known that mercury 

 is very largely used in mining operations, as well as for ba- 

 rometers, thermometers, voltaic batteries, and points ; and we 



