1821.] Prof . Berzelius on the Composition of Prussiate». 301 



three and a half feet of coal gas, the comparison between the 

 Derby prices and Mr. R.'s statement of oil gas will stand thus : 



£ s. d, 



lOOOfeet ofoilgas cost 17 



3500 feet of coal gas is sold at Derby for. . . 16 3 



9 

 leaving a balance of del. in favour of coal gas besides the profit, 

 which the Company calculate at 10 per cent. The comparison 

 between oil and coal gas by experimentalists in general is given 

 as 1 to 3 : allowing this to be nearly the truth, we shall have 

 the following statement : 



Mr. Ricardo says that a fair average for 



^ s. d, 

 1000 feet of oil gas, allowing for wear, tear, 



and every contingence, is 1 10 



3000 feet of coal gas sells in Sheffield for. . 1 11 6 



Now if we allow that oil gas can be manufactured at 305. per 

 1000 feet, selling it at the same price as coal gas, in proportion 

 to its illuminating power, it would only leave 5/. per cent, sup^ 

 posing that there should be no losses. Mr. R. further remarks, 

 that " the only possible inconvenience that can result from the 

 use of oil gas is an accidental smell from the cock being acci- 

 dentally left open, which is instantly detected, and as instantly 

 remedied without leaving so unpleasant a smell as that arising 

 from the similar escape of coal gas." I think that there is very 

 little difference between the smell of oil and coal gas as to plea- 

 santness ; but allowing that the smell of coal gas is more unplea- 

 sant than that of oil gas when an escape takes place, that should 

 not be urged as a reason why oil gas should have the preference y 

 for as both gases, when mixed with a certain proportion of 

 atmospherical air will explode when a light is introduced, it is 

 my opinion, that the gas most proper to be introduced in dwell- 

 ing-houses, warehouses, &c. is that which can be most easily 

 detected when an escape rfoes take place. 



If these remarks merit a place in your journal, your inserting 

 them will obhge A Subscriber. 



Article XIV. 



Ilesearches on the Composition of the Prussiates, or ferruginous 

 Hydrocyanates, By J. Berzelius. 



iContinued from p. 222.) 



I PROCEED to detail the experiments I have made with the 

 design of obtaining light on these subjects, and the inferences 

 which I think may be deduced from them. . 



