in the Economising of Fuel. 175 



hours there is a very slight diminution in volume. Though the 

 sponge does not cause any immediate action, yet an action does 

 occur when they are kept together for some time. In one in- 

 stance the mixture exploded on the fourth day ; and in another, 

 in which case it was put over the sponge on a Friday, it explod- 

 ed at some time during the Sunday. 



These experiments also shew that in its action with spongy 

 platinum, the gas differs from light hydro-carbon. According to 

 Henry a mixture of it and oxygen is not acted on by the sponge, 

 even when heated to 555°. 



When the gas is exposed to the action of chlorine over water, 

 there is no action in the dark ; but on exposure to sunshine, 

 muriatic and carbonic acid are formed. The amount of conden- 

 sation I have found to vary, but in no instance did the gas con- 

 sume nearly as much chlorine as light hydro-carbon does, which 

 requires no less than four volumes for complete condensation ; 

 and yields its own volumeof carbonic acid and eight of muriatic, 

 four of which are formed by the hydrogen of the water, the 

 other four by that in the gas. The gas evolved by the action of 

 steam on coke never gave so much as half its volume of carbonic 

 acid, and not much more than its own bulk of muriatic acid, 

 shewing evidently that it contained a very small quantity of hy- 

 drogen, in comparison with that in hydro-carbon. 



From the experiments which have now been related, there 

 can, I think, be no doubt, that if any hydro-carbon exists in the 

 gas, it must be in very trifling quantity ; but as carbonic acid is 

 formed, both during its combustion, and also by its action with 

 chlorine, carbon must exist in it, and if so, supposing it not in 

 union with hydrogen, the only other state of combination in 

 which it can be, must be with oxygen, in the form of carbonic 

 oxide. 



That the gaseous fluid is merely a mixture of carbonic oxide 

 and hydrogen, may, I think, be inferred from what happens du- 

 ring its formation, taken in conjunction with the facts above 

 mentioned. In one instance the gaseous product evolved by 

 passing steam over charcoal, previously well heated, was collect- 

 ed over mercury, and treated with potassa, by which it lost J 8 

 per cent., of course, of carbonic acid. Now, if the whole of the 

 oxygen of the steam had united with carbon, to form carbonic 

 acid, and supposing the hydrogen in the state of hydro-carbon. 



