862 Memorandum of Experiments, fyc. [Oct. 



On pulling to the spot we found the river absolutely thickened by 

 the wreck and cargo of the vessel. By subsequent examination, it 

 was found that with the exception of the forecastle, the " Equitable" 

 had by this explosion been literally torn to pieces. The fishing boat, 

 battery, watch, &c. were all "expended." — The ladder conductors were 

 however picked up uninjured half a mile from the wreck. 



In conclusion of this paper — which circumstances induce me to pub- 

 lish sooner than I intended — I think it but just to express my thanks for 

 the zealous assistance afforded me in alL the preceding experiments, and 

 in the construction of the apparatus, by Mr. Siddons, of the Medical 

 College. 



I should add, that while my experiments were proceeding, my col- 

 league Mr. Egerton, suggested the placing of a strip of saltpetre match - 

 paper round the platinum, in preference to placing this in contact 

 with the powder. The excellence of the suggestion was proved 

 by experiment, for we found on repeated trials that saltpetre match 

 inflames at nearly double the distance at which the wire will explode 

 powder. 



The match should be prepared by immersing cotton in a saturated 

 solution of the purest saltpetre; if the salt be impure the match is 

 liable to become damp, and thus to frustrate the experiment. A few 

 fibres of this cotton should be twisted loosely round the platinum wire. 



It is astonishing to observe the great cooling effect produced on the 

 platinum wire by the contact of apparently dry powder, if this be in 

 the least degree damp. On one occasion with a new battery in perfect 

 order, with dry conductors only 150 feet long, the standard platinum 

 wire was kept for an hour in a pint bottle of powder just drawn from 

 the canister, and no explosion ensued ; but by removing some of the 

 powder, so as to leave only a grain or two on the wire, the mass being 

 half an inch below it in the neck of the bottle, explosion took place the 

 instant the battery contact was effected. 



I wish it to be remembered too that the preceding experiments are 



applicable only to explosions in fresh water ; operations in salt water 



would require a special set of experiments, which I have not had the 



means of instituting on a sufficiently large scale. I have strong reason 



however to believe that the cork conductors with pitched wires will 



