tMO Mr, Ricardo on the Comparative Advantages [March, 



■power. If we take the mean of these statements, it will be as 

 one to three and a half; that is, 20 cube feet of oil gas will give 

 «s much light as 70 of coal gas. 



Oil gas requires no purification ; it contains no sulphuretted 

 hydrogen which is one of the admixtures of coal gas, and of this 

 all the purification to whi<h it is submitted cannot wholly 

 deprive it; the coal gas, therefore, acts upon all metallic sub- 

 stances, and in the course of time must seriously injure the 

 pipes through which it passes, and its accidental escape in shops 

 and houses must prove highly detrimental to all ornamental 



fildings, paintings, or any thing of which metals form a part, 

 his cannot happen where oil gas is used ; for it contains no 

 sulphuretted hydrogen, und it is well known to have no action on 

 inetals whatever. It may be said, that the mode adopted for 

 purifying coal gas effectually deprives it of this noxious gas ; but 

 expeiience has proved that this is not the fact, as in many places 

 the smaller copper pipes show evident marks of being strongly 

 acted upon, the bore being gradually filled up with sulphuret of 

 copper. As this process takes place slowly, the diminution of 

 light is not immediately perceptible, but it v/ill become very 

 evident after a time ; and it may be expected that after the lapse 

 of a still longer period, the same evil may arise in the larger 

 pipes, as iron is also liable to the same corrosive influence from 

 Its contact with this gas. The admixture of sulphuretted hydro- 



fen with coal gas must prevent its general introduction into 

 ouses, as the sulphurous acid gas, which is given outdaring its 

 combustion, would prove very annoying in a confined room, 

 besides which, from the consumption of so much larger a portion 

 of coal than oil gas to produce the same light, a greater quantity 

 of moisture is generated, and much more heat is given out. 



From the above statement, it is very evident that the smaller 

 bulk and greater purity of oil gas will allow of its employment in 

 dwellmg houses without its producing the least inconvenience^ 

 If the pipes are well fitted together and properly proved before the 

 gas is admitted into them, no annoyance whatsoever need be 

 apprehended ; and if a cock should be accidentally left open, 

 and the gas allowed to escape, it may be immediately remedied 

 without leaving so unpleasant a smell as that arising from the 

 similar escape of coal gas. 



When any new improvement is introduced, we are too apt ta 

 place any possible inconvenience that may result from it in an 

 exaggerated point of view, and wholly tc overlook those we are 

 labouring under, and which it is intended to supersede. Thus 

 the only possible inconvenience that can result from the use of oil 

 gas is that which I have before mentioned, an accidental smell from 

 carelessness, instantly detected, and as instantly remedied — an 

 inconvenience to which we are equally liable in our present mode 

 of lighting, in addition to which there is the trouble of trimming 

 the lamps, the chance of spilling the oil, not a very unfrequent 



