242 On Mr. Ricardo's comparative Advantages 



Let us examine liow Mr. Ricardo has come to the knowledge 

 that " one foot of oil gas is equal to four of coal gas." This is 

 the grand point of attraction held out to the admiration of the 

 public; and one on which an flatly contradictor)' evidence has 

 been borne, as distinguished tlie late memorable proceedings in the 

 Court of Common Pleas, Thus, whilst Mr. Deville, of the Strand, 

 is inclined to compare oil gas with coal gas in the ratio of 9 to 5, 

 and while Mr. Brande, in his Manual of Chemistry, p. 156, says 

 that " from two to three cubic feet may be regarded as equiva- 

 lent to five or six of coal gas," we have every other intermediate 

 proportion, even as high as Mr. Ricardo's Jour to one. Mr. R. 

 says, " I have found that an Argand burner giving a light equal 

 to six candles, six to the pound, consumed one cubical foot in 

 the hour." What was the specific gravity of the gas made use 

 of, or what the kind of candle (wax or tallow), the number of 

 threads in each wick, or the weight of each consumed, we are 

 not informed. This we know, that Professor Brande states that 

 '' an Argand burner of oil gas giving the light of eight wax can- 

 dles (four to the pound) was found to consume 3900 cubical 

 inches, or rather more than 2| cubic feet per hour." 



But to proceed with Mr. R ,'s statement, which is now brought 

 into comparison with some results of Mr. Accum, who states, 

 in his work on Gas Lights, p. 276, that " an Argand burner of 

 coal gas giving a light equal to three candles (eight to the pound) 

 consumes two cubical feet per hour." These are the species of 

 data from which conclusions so satisfactory to Mr. Ricardo have 

 been deduced ! 'Tis well he refers us to p. 276, for at other pages 

 of this genuine book-maker, I can find divers ratios to suit any 

 theory ! So much for the comparison of one discrepancy with 

 another. But if one volume of oil gas is not equal to Jour of 

 coal gas, of which Mr. R. himself seems to have some misgivings, 

 for "three and a half" is ultimately the foundation upon which 

 he raises his allegations against coal gas, surely it can be well 

 atUhenticated as being equal to three volumes ! for he says "the 

 quantity of light produced from a given quantity of oil gas is 

 stated by an eminent chemist to be equal to three times the 

 quantity produi ed from coal gas." 



Who this eminent chemist is, we are left to conjecture: it 

 surely cannot be Dr. Henry *, who has written most elaborately 

 on tlie subject, and more to the point than any one. Possibly it 

 may be Professor Brande, because he said at the Eakerian lec- 



* See papers of his in Nicholson's Journal for 1805, vol. xi; in the 

 Transactions of the Royal Society for 1808 : and in the last volume of the 

 Manchester Meraoirs. Another pujjcr of his on the same interesting sub- 

 ject has lately been read by him before tiie Royal Society, which perhaps 

 will shortly appear. 



turc. 



