130 Dr Bischof s Examination of Three Inflammable Gases 



the height of the internal mercurial level above the external 

 was subtracted from the height of the barometer. 



The gaseous mixture driven out of the bottle by heat was 

 naturally at a maximum of moisture. The residue of gas was 

 in a similar condition after the detonation. According to the 

 well-known formula of Dalton, this watery vapour was sub- 

 tracted from the volume of the mixture of gases. The resi- 

 due of gas, after the absorption of the carbonic acid by solid 

 potash, was of course no longer moist, as the potash had ab- 

 sorbed the watery vapour as well as the carbonic acid. 



The pit-gas, which, in order to separate the carbonic acid, 

 had been washed with solution of potash, was detonated with 

 three times its volume of oxygen. The following results of 

 my experiments give the measured volumes, after subtracting 

 the watery vapour and after reducing to 32° F., and 28 inches 

 B. (German). 



Expor. 1. Exper. 2. Exper. 3. Mean. 



Mixture of gases, .... 4 4 4 4 



Absorption after detonation, . 1.9515 1.9632 1.9457 1.9535 



Absorption by means of potash, . . 1.0575 1.0284 1.0339 1.0399* 



I shewed, seventeen years ago,t that the analysis by the de- 

 tonation-tube, of a mixture of gases consisting of one or two or 

 three inflammable gases, affords the true composition if the 

 mixture is composed of hydrogen and carbonic oxide gases, 

 or of hydrogen and carburetted hydrogen gases, or of carbonic 

 oxide and olefiant gases, or of carburetted hydrogen and ole- 

 fiant gases ; that, on the other hand, if the mixture consists of 

 any other two or three inflammable gases, the above-men- 

 tioned absorption by detonation, and that by potash, are ob- 

 tained in such relations that it remains undetermined whether 

 the gaseous mixture consists of this or that combination. In 

 order, in these last cases, to come to a decision, it must be 

 ascertained whether or not olefiant gas is present. By means 



* When I performed these experiments I was not aware of all the cir- 

 cumstances mentioned above, by attention to which the most accurate re- 

 sults are obtained. Hence, in the results given, there is not the same near 

 agreement which was afforded by my later experiments. 



t Contributions to the analysis of gaseous mixtures of hydrogen, carbonic 

 oxide, carburetted hydrogen, and olefiant gases, in the Journal far Chemie 

 and Phyrik, t. xxxvii. p. 133. 



