270 Dr. Henry on the Analysis of Gaseoiis Mixtures 



Deen completed till several days have elapsed. On mixtures 

 of olefiant gas, of carburetted hydrogen, or of cyanogen, with 

 oxygen, the sponge does not by any duration of contact exert 

 the smallest action at common temperatures. 



It was this inefficiency of the platinum sponge on the com- 

 pounds of charcoal and hydrogen in mixture with oxygen, 

 while it acts so remarkably on common hydrogen, and also, 

 thouo-h slowlj', on carbonic oxide, that suggested to me the 

 possibility of solving by its means some interesting problems 

 in gaseous analysis. I hoped more especially to be able to 

 separate from each other the gases constituting certain mix- 

 tures, to the compositions of which approximations only had 

 been hitherto made, by comparing the phaenomena and results 

 of their combustion with those which ought to ensue, suppos- 

 ing such mixtures to consist of certain hypothetical propor- 

 tions of known gases. It might, for instance, be expected that 

 from a mixture of hydrogen and carburetted hydrogen with 

 oxygen, the platinum sponge would cause the removal of the 

 hydrogen, leaving the carburetted hydrogen unaltered. To 

 ascertain this and a variety of similar facts, I made artificial 

 mixtures of the combustible gases in known volumes ; and sub- 

 mitted them, mixed with oxygen, sometimes to contact with 

 the sponge, and sometimes with the balls made of clay and 

 platinum, described by Professor Dcebereiner. 



Section I. 



On the Action of finely-divided Platinum on Gaseous Mix- 

 tures at common Temperatures. 



I. Mixtures of Hydrogen and Olefiant Gases "with Oxygen. 



When to equal volumes of olefiant gas, and an explosive 

 mixture (which is to be understood, whenever it is so named, 

 as consisting of two volumes of hydrogen and one of oxygen 

 gases), one of the platinum balls, recently heated by the blow- 

 pipe, and allowed to cool during eight or ten seconds, is in- 

 troduced through mercury, a rapid diminution of volume takes 

 place; the whole of the hydrogen and oxygen gases is con- 

 densed ; but the olefiant gas is either not at all or very little 

 acted upon. In a few experiments when the tube was narrow, 

 and the quantity of mixed gases small, the olefiant gas escaped 

 combustion entiiely; but, in general, an eighth or tenth of it 

 was converted into water and carbonic acid. It is difficult, 

 however, to state the precise proportion of any gas which, 

 when added to an explosive mixture, renders the latter insen- 

 sible to the action of the balls or sponge ; for much depends 



on 



