70 Notice of some recent additions to Chemistry. 



deleterious effect to the agency of this gas. lie has observed 1 per 

 cent of this gas to destroy an animal in two minutes, which is at 

 variance with the statement of Nysten. This observation explains 

 many of the inconsistencies which appeared some years ago in tho 

 evidence of some London chemists respecting the influence of Joyce's 

 stoves. It is quite obvious that their structure was dangerous. Le- 

 blanc found that a candle was extinguished in air containing 4i or 6 

 per cent of carbonic acid. In such an atmosphere life may be kept 

 up for some time, but respiration is oppressive, and the animal is 

 affected with very great uneasiness. Air expired from the lungs con- 

 tains about 4 per cent, of carbonic acid, and hence this atmosphere is 

 noxious. Even 3 per cent in the atmosphere killed birds, and yet we 

 have seen statements which affirmed that upwards of 3 per cent had 

 been detected in the London theatres. All these facts are pregnant 

 with importance in reference to health. Our miners may not be 

 suffocated by fire-damp explosions, but we should remember that their 

 constitutions may be poisoned by the respiration of tainted atmos- 

 pheres. 



No one can have failed to remark the immense loss of illuminating 

 gases sustained in the iron works of this country. We are not aware 

 of any experiments which have been made upon their composition. 

 But in Germany and France, where fuel is more scarce than in this 

 country, economy has induced chemists to examine the nature of tho 

 loss in such circumstances. According to Ebelmen, (Ann. de Chim. 

 V. 153.) in furnaces where charcoal is used, the gases at the mouth of 

 the furnace consist of 13 per cent, carbonic acid, 23^ carbonic oxide, 

 6 per cent hydrogen, and 58 azote. As we descend in the furnace, 

 the carbonic acid and hydrogen diminish, tiU we arrive at the widest 

 part, where there is no carbonic acid, and only 2 per cent hydrogen. 

 The carbonic oxide and azote, however, increase in descending, and 

 amount in the same part of the furnace to 35 per cent of tho former* 

 and 63 of the latter. It would appear that when the air is blown into 

 the furnace, it is first converted into carbonic acid, and then rapidly 

 into carbonic oxide, thus rendering latent an immense quantity of 

 heat, and that the heat of the hot blast furnace has its efficacy limited 

 to the lower part of the furnace. Dr. Bunsen, who made some import- 

 ant observations on this subject in 1839, (Poggendorflf, Ann. xxxvi. 198.) 

 showed that 50 to 75 per cent of the combustible materials are lost 

 in the form of carbonic oxide ; that it would be impossible to use tho 

 waste gases with cold air for the smelting of iron ; but that they might 

 be employed, if collected at the temperature at which they exist when 

 evolved, in conjunction with the hot blast. 



The use of gases as illuminating agents is so important, that every 

 method of obtaining them by economical means deserves attention. 

 The employment of pure oxygen is daily becoming more extended. 

 Mr. Balmain has lately applied (L' Institut 458.) the well-known 



