1821.] on Oil and Coal Gas. 45 



six to the pound ; and of six of these jets, consuming one cubic 

 foot of gas per hour, gave a light equal to six of the above- 

 mentioned candles. Mr. Low has argued upon this point, but 

 he has shown nothing to disprove it. In estimating the quan- 

 tity of gas produced from a given quantity of oil, at 100 cubic 

 feet per gallon, I am borne out by the most correct information 

 which I can obtain from various places where oil gas is used, 

 where the average quantity of gas obtained rather exceeds what 

 I have stated. 



Mr. Low next endeavours to prove my statement contradic- 

 tory, because I say that oil gas requires no purification, but 

 that it is passed through a wash vessel ; and he takes this op- 

 portunity of asserting, that in some places, where oil gas is 

 used, the parties have been threatened with an indictment for a 

 nuisance, for allowing the water through which the oil gas passes 

 to run down the drains. Without thinking it necessary to en- 

 quire whether there is any analogy between the passing of oil 

 u;as through water, to condense any vapour that may come over 

 with it, and the separation of sulphuretted hydrogen from coal gas, 

 by means of lime, I would ask Mr. L. where it is that the par- 

 ties have been so threatened, and from whence he could possibly 

 have obtained this information '. In contradiction to this state- 

 ment, I think I may assert as a positive fact, that in no one in- 

 stance whatever, where oil gas is made with a proper apparatus, 

 that is, the apparatus made by Messrs. Taylor and Martineau, 

 and I know of no others, does any water, which comes in con- 

 tact with the oil gas, ever pass down any drain. And I am fur- 

 ther authorized to assert a circumstance that I was not before 

 acquainted with, that, from a late improvement in the condens- 

 ing vessel, the oil gas does not pass through, or come in contact 

 with, any water at all, until it reaches the gasometer. 



I think I have pretty clearly proved that my statement that 

 oil gas requires no purification is perfectly correct ; and had 

 Mr. Low been better acquainted with its nature, he would 

 not have hazarded the observations he has made on this point. 

 In the purifying of coal gas, (for no one will deny that that re- 

 quires purification,) I believe that the consumers of it have daily 

 experience that it is not completely effected; and there are spe- 

 cimens of pipes to be seen which have been so acted upon by 

 this p;as as to be almost impervious. 



1 should hardly have condescended to notice the wonder and 

 astonishment which Mr. Low expresses at the quantity of gas 

 which I have stated 1000 lights will consume, during the 

 longest night, and the number of retorts required to produce it, 

 but that some might suppose, from his notes of admiration 

 and italics, that I had advanced something very absurd. On 

 referring to my paper in the Annals for March last, it will be 

 seen that, for the sake of argument, I supposed two establish- 



