1823.] of Oil Gas Establishments. 223 



the present, I need only say, that the quantity of light may be 

 augmented or diminished by different modifications of burners, 

 by lessening or increasing the pressure of gas, at the same time 

 enlarging or diminishing the external hole through which it 

 passes. Indeed in measuring the proportions of light produced 

 from oil and coal gas, there are so many circumstances to be con- 

 sidered, that no two experimentalists would be satisfied with the 

 results obtained by others. The most satisfactory proof which can 

 be brought forward is the practical result of observations made by 

 a disinterested and intelligent consumer, and which is shown by 

 a computation of pounds, shillings, and pence, more intelligible 

 to those usually interested in gas concerns than all the philoso- 

 phical or chemical experiments that can be tried. 



I hope, from what I have above stated, it will not be supposed 

 that I mean to underrate the advantages of science ; you, Sir, I 

 am sure, know me well enough, and have been sufficiently 

 acquainted with my pursuits, to exonerate me from such a 

 charge; but the present question is not so much one of science 

 as it is of economy and utility ; and in such a question, practical 

 experience would certainly take the lead of scientific experi- 

 ments. We all know the results of the inquiry on the famous 

 oil question, which will not readily be forgotten. It must have 

 had the effect of teaching the public, that in similar points of 

 dispute, they must look to other authorities than the mere dicta 

 of scientific men ; and no authority can be more satisfactory 

 than that which results from the agreement of scientific experi- 

 ments with practical results. 



I would have transmitted to you a copy of the report of the 

 Oldford Oil Gas Company, but it is not yet printed : it details 

 the progress of the concern, and expresses the satisfaction 

 of the Committee with the favourable account which they are 

 enabled to lay before the Proprietors, and bears testimony of 

 the correctness of all the statements which were made by 

 Messrs. Taylor and Martineau at the commencement, in all of 

 which they have been fully borne out after a fair and satisfactory 

 trial. I am, yours, Sec. M. Ricardo. 



Article XIII. 



Abstract of a Memoir entitled " An Attempt to ascertain the 

 Chemical Composition of those Minerals which possess the same 

 Crystalline Form as Pyroxene." By H. Rose.* 



The author of this paper observes, that there are many mine- 

 rals which, from whatever place obtained, always possess the 



• From Schweigger's Journal, vol. v. New Scries. 



