168 ILLUMINATION. [VI. 



from the muriate by the carbonate of ammonia, becomes sub- 

 carbonate, and ultimately sesqui or peroxide of iron. 



According to the inventor, the sulphuret of carbon is also 

 removed during the operation, and the illuminating power of 

 the gas thus augmented about 8 per cent., with but slight 

 expense for material and a great economy as to wear and 

 tear of apparatus. 



Gas-lime. — Graham's examination of gas-lime exposed to 

 the air for a few hours after use, was composed of — 



Hyposulphite of lime 12.30 



Sulphite " 14.5T 



Sulphate " 2.80 



Carbonate " 14.48 



Caustic lime 17.72 



Free sulphur 5.14 



Sand 0.71 



Water 32.28 



100.00 

 In this state it is well adapted to the preparation of hypo- 

 sulphite of soda, for which purpose it is extracted with water, 

 the solution decomposed by carbonate of soda, and evaporated 

 to crystallization. The hyposulphite of soda thus obtained 

 may be used for the daguerreotype, and might possibly be 

 used instead of common salt to extract silver from its ores. 

 By proper calcination, gas-lime may be converted into a mix- 

 ture of nearly equal parts of sulphate and carbonate of lime, 

 in which state it may be employed in agriculture and other 

 arts. (Rep. Pat. Inv. 1845.) Eisner draws attention to its 

 value for removing hair from hides. 



NapJtthalizing Gfas. — Among the many patents for naph- 

 thalizing gas, is one in Lend. Journ. xxxvii. Aug., in which 

 the heat of the burning jet is communicated by metal to a 

 vessel containing a hydrocarbon. The gas, in passing through 

 this vessel, takes with it a portion of the hydrocarbon, passes 

 into a sphere over the jet, where it is heated, and then passes 

 out at the jet. It is supposed to yield a whiter light. There 



