404 Mr. Elliott on Oil Gas. 



choked xip from a partial accumulation *. But, what is best, 

 that which annoyed, now contributes to your advantage ; it 

 becomes chemically combined with the hydrogen, is thrown 

 off when that body is ignited, and during its transformation 

 into carbonic acid surprises with the brilliancy of its combus- 

 tion. As the general result of my experiments I may state, 

 that after the introduction of the oil into the retort, the sooner 

 it is made into gas the more we obtain ; and the sooner the gas 

 is got out of the retort after it is made, the moi'e durable it is. 

 On this account, its passage into the gasometer should be faci- 

 litated by the tube having a large bore. 



The last difficulty which I had to encounter was, to make 

 the gas permanently good ; and the mode which I have just 

 described adds this to its other advantages. Foi'merly, when 

 a low heat was employed, and the gas suffered to remain un- 

 consumed for a few weeks, it was mcapable of affording light, 

 from a precipitation of the combined carbon. The flame was 

 a deep blue, similar to that exhibited during the combustion 

 of hydrogen, obtained from the decomposition of water. On 

 the improved method, I have kept the gas for many weeks 

 without perceiving any diminution in its power of affording 

 light ; and as the additional dose of carbon increases its illu- 

 minative power, of course a much smaller quantity of gas is 

 consumed in a given time. There is another singular fact to 

 which I must call your attention, viz. that good gas — that is, 

 gas containing its maximum dose of carbon — burns for a much 

 longer time than when it contains only a minor portion ; or, in 

 other words, that a much less quantity of the former, under 

 the same pressure, would pass through a given space, in a cer- 

 tain time, than of the latter. It is advisable, when the gas is 

 made, that it should not be formed under pressure ; the coun- 

 terbalance to the gasometer should rather have the prepon- 

 derance, which materially facilitates its formation, and prevents 

 a deposition of carbon, which not unfrequently takes place 

 when working under a material weight. 



These sentiments agree with the views of Dr. Henry, whose 

 paper, " On the Aeriform Compounds of Charcoal and Hy- 

 drogen," was read before the Royal Societ}' in March 1821, 

 and contains the following notice as the general issue of his 

 experiments : — That oil gas, as he had formerly shown with 

 respect to coal gas, is very far from being uniform in compo- 



* I mention this as an accident likely to occur where the heat applied is 

 not kept up. In examining a small apparatus which exploded, I found that 

 the accumulation of carbon had stopped up the tube through which the 

 gases passed to the gasometer. 



sition, 



