-GALVANIC AND ELECTRICAL EXPERIMENTS. ^05" 



XIV. 



Later from Mr. CvTHBUKTiON refpeSting Ids Galvanic and 

 EkBrical Experiments. 



To Mr; NICHOLSON. 

 Dear Sir, 



In confequence of the note which you have beenfo obliging Introduaion. 

 as to add to my letter, addrefled to Dr. Pearfon, inferted in 

 your Journal for this month, I have to fay, that the troughs 

 were ufed collaterallj/ : I fliall now be happy to fee your re- 

 marks. It appears, that I ought to have been more explicit, 

 and therefore, I beg leave to offer the following additional 

 obfervations *. 



The two laft mentioned experiments in the letter alluded 

 to, were compared with common eleflrica! difcharges, with 

 a view to prove what quantity of coated glafs would be re- 

 quitite to ignite the fame lengths of wire. 



Two jars, each containing about 170 fquare inches of coated ^xperimant. 



•> ' o ^ Dcflageiation of 



furface, were fet to the condu6lor of a 24- inch fingle plate wire by jars. 



eledtrical machine, with my univerfal electrometer loaded 



with 31 grains, (fee Quarto Journal, Plate XXII. Vol. II.) 



* I ought certainly to have mentioned the arrangement of the 

 troughs, and likewife I ought not to have faid fo vaguely, that 

 double quantities of galvanic fluid, only burn double lengths of 

 wire, becaufe I am ftrongly of opinion, that the reafon why gal- 

 vanic difcharges from troughs do not aft upon metals in the fame 

 ratio as common eleftric difcharges do, proceeds from fome defe6l 

 in the arrangement, and alfo conltruftlon. 



I find in my notes of improvements for the 6th of June, 1803, ^''^ "^ '^'^8* 

 that I had made a pile of 16 pairs of plates of 10 inches diameter, ^ ^ "* 

 and that eight of them laid upon each other in the ufual manner, 

 with cloths wetted with diluted muriatic acid, burned one inch of 

 wire of l-193th part of an inch in diameter, and that 16 pairs 

 burned four inches of the fame wire. This experiment was re- 

 peated on the 8th of June, with the fame refult, with refpeft to 

 metals, but gave ftrong and loud fparks from metal to metal, fuf- very loud gal- 

 ficient to be heard at 300 yards diftance, which refult, I believe, vaoic fparks. 

 has never been obtained from troughs, foas to be heard, indeed, at 

 any diftance. For the laft experiment, the cloths were wetted in 

 a ftrong folution of muriate of ammonia. 



Eight 



