^a Mr. Fownes on the Equivalent of Carbon. 



only three times immersed in the acid, and only for about two 

 seconds each time. I tried the same battery at 268 feet, and 

 did not succeed. The plates were then well washed, and fresh 

 exciting liquor made : the experiment again failed ; the plates 

 were quite inactive. The next day I tried the same plates 

 and the same exciting liquor, and succeeded at 268 feet. 

 From this it seems impossible to say how many pairs of plates 

 would be required to produce uniform effects at long distances. 

 I suspect that the zinc plates do not act equally in producing 

 the electricity, which causes this variation. 



I should have liked very much to have tried the conduct- 

 ing properties of different sized wires, but had not an oppor- 

 tunity of getting them here. 



Not having seen any notice of this novel and safe me- 

 thod of blasting in your excellent journal, induced me to 

 send you these few remarks. 



I believe I am the first in Ireland that applied the galvanic 

 battery instead of the fuze in blasting. 



I remain. Gentlemen, yours, &c. 



Hamilton K. G. Morgan. 



XII. On the Equivalent of Carbon. By Mr. George Fownes. 



ToR. Phillips, Esq. F.R.S. 4 c. 

 Sir, 

 TJAVING read with great interest an extract from the 

 -■- " Journal de Pharmacie^'' in your Number for February, 

 on the composition of naphthalin, by M. Dumas, and the pro- 

 bability, in his opinion, of the existence of an error in the 

 commonly received combining number of carbon, I beg to 

 send you an account of some recent analyses of that substance, 

 and also of three other compounds of hydrogen and carbon, 

 made in the laboratory of the Middlesex Hospital Medical 

 School : I must leave it to you to decide whether these expe- 

 riments are of a proper kind to occupy a page of your Journal 

 in the absence of more original and important matter. 



The subject of the composition of naphthalin has engaged 

 the attention of chemists ever since its discovery, and notwith- 

 standing the care which has been bestowed on its analysis, the 

 results differ more than ought to be expected from processes 

 so accurate as those employed in the investigation. There is 

 one circumstance, however, to be remarked in nearly all, 

 namely, that the sum of the weights of the hydrogen and car- 

 bon obtained by experiment, always exceeds that of the sub- 



