330 Dr. W.C. Henry's Experiments on Gaseous Interference. 



were left, which were not diminished by washing with potassa. 

 Even when the vokime of the defiant was double that of the 

 explosive mixture, there was instant action, though to a less 

 extent than in the last experiment. 



When the volume of the olefiant was three times that of the 

 explosive mixture, no immediate action was visible, though a 

 notable diminution always took place in the course of a few 

 hours or on the following day. Finally, the activity of the 

 black pow^der of Liebig was not suspended by the addition of 

 twenty volumes of olefiant to one of explosive mixture. 



On subjecting to examination the gaseous products of these 

 and other experiments on olefiant gas, mingled with various 

 proportions of the explosive mixture, very different results 

 from those afforded with carbonic oxide were obtained. In 

 the greater number of experiments with olefiant gas, no ap- 

 preciable diminution was caused by prolonged contact, or by 

 subsequent washing with potassa; and though in some cases, 

 when the explosive mixture considerably exceeded the olefiant, 

 there vias a perceptible absorption, yet the carbonic acid thus 

 evidenced was always of small amount. In three successive 

 experiments, in which olefiant gas and explosive mixture were 

 mingled in equal proportions, there was no measurable pro- 

 duct of carbonic acid. Yet in all these cases, though the ball 

 ascended rapidly on first contact, its activity was soon sus- 

 pended. Olefiant gas then possesses, like carbonic oxide, an 

 undoubted power of retarding the union of hydrogen and 

 oxygen, but it differs from carbonic oxide in not necessarily 

 affording carbonic acid by so acting. 



Similar differences presented themselves on submitting mix- 

 tures of olefiant and oxygen only to the action of platina. To 

 the observation of Dr. Faraday, " that the most prolonged 

 contact with the prepared plates never induced the union of 

 the elements of olefiant with oxygen," I may add, that the 

 contact was not efficient, even when aided by the presence of 

 liquid potassa. The spongy metal, similarly conjoined with 

 potassa, was also for the most part entirely inert, and in the 

 few instances in which carbonic acid appeared, it was formed 

 very slowly, and in small quantity. At the temperature 480° 

 Fahrenheit, however, the sponge has been shown to occasion 

 the speedy though inexplosive combustion of olefiant in mix- 

 ture with oxygen. Liebig's powder too caused the slow com- 

 bination of the two gases at atmospheric temperatures, as was 

 evidenced both by considerable diminution of volume, and by 

 the test of lime-water; and when the tube containing the 

 gaseous mixture and powder was surrounded with boiling 

 water combination ensued with rapidity. Now the mode in 

 which platina acts is of course identical in the various states 



