40 PYROMETALLURGY. [ill. 



carbonic and sulphurous acid. 20 grm. cane-sugar yield 2 

 litres gas, of which about ^ is carbonic acid. We give this 

 method of obtaining carbonic oxide, on account of its import- 

 ance as a reducing agent, in order that experiments may be 

 instituted with it. 



1. Pyrometallurgy, 



Or the operations upon metallic ores by fire. 



Iron. — Wrightson's examinations of ores and iron from 

 Staffordshire, and of the influence of the hot-blast, see in 

 Chem. Gaz. vii. and viii. and Journ. Fr. Inst. (3) xvii. 201. 



For one of the most able investigations into the operations 

 of the blast furnace, by Bunsen and Playfair, see Journ. Fr. 

 Inst. (3) xvii. 268, 338, 387 ; xviii. 24, 136, 218. On the 

 manufacture of iron in South "Wales, see Journ. Fr. Inst. (3) 

 xix. 339. 



Application of the Waste-gases of Blast-furnaces. — The 

 masterly investigations of Bunsen on the working of blast- 

 furnaces, above cited, have shown, that, under ordinary cii*- 

 cumstances, | of the heat produced is lost. The use of the 

 waste-gases, proposed and executed in Germany, has been 

 successfully carried out in Pennsylvania and other States, in 

 many furnaces, especially where anthracite is employed, and, 

 we believe, without serious detriment to the working of the 

 furnace ; therefore, with greater economy of fuel, where boil- 

 ers and an engine are employed for blowing. Mr. S. Colwell, 

 of Philadelphia, succeeded so perfectly in abstracting the 

 waste-gases, that, while the furnace was fully charged and 

 doing its usual work below, we have stood upon the charge 

 with impunity, without feeling the heat or observing the stifling 

 sensation of carbonic acid and other gases from the combus- 

 tion. It is surprising, therefore, to observe that the experi- 

 ments in Wales have turned out unfavorably, as reported in 

 the Journ. Fr. Inst. (3) xx. 277, and we think the remarks of 

 a collaborator just. 



While on this point, we cannot forbear mentioning the white 



