224. 



Th« gafes ob- 

 tained from 

 water by galvan. 

 ifm, fmellcd of 

 nitrous gas after 

 explofion, and 

 gave nitre with 

 pota/h. 



On Pacchlonl 

 and Riffaat's 



experiments. 



Agaifift the 

 doftrine of the 

 compofition of 

 water : it is 

 urged that the 

 gafes obtained in 

 galvanifm vary 

 from different 

 caufest 



COMPOSITION OF WATER, &C. 



I was glad to fee my experiments in your Journal, as it has 

 fo extenfive a circulation. I fliall now give you the analyti- 

 cal part to confirm my former experiments; as by them I had, 

 I hope, given ftrong eridence, that acids are neceflary in 

 forming gafes. Having collected a great quantity of the gafes 

 produced by the galvanic pile, I introduced them into a ftrong 

 glafs tube, doled at one end, the other end I afterwards 

 ciofed, having previoufly introduced to the gafes a fmall quan- 

 tity of a folution of potafli : through this tube the eledric fpark 

 was made to pafs, it having fmall openings to admit the wires 

 of communication. Upon their corabuftion, the fmell of the 

 nitrous acid vapour appeared, both from its colour and fmell; 

 and the tube being moved up and down, fo as to allow the 

 vapour and tlie folution of potafti to come in contadl ; the fo- 

 lution being examined forae fhort time after, it gave evident 

 and unequivocal /igns of the nitrate of potafh. 



I fee in your Journal, Mr. Riffant's experiments, in anfwer 

 to Mr. Pacchiani's paper. Indeed, in reading Mr, P.'s ex- 

 perinienls, nothing could appear more vague and wild than 

 that water, by having oxigen, the fuppofed acidifying princi- 

 ple, taken from it, (hould become a ftrong mineral acid. Mr. 

 RifFant's fecond experiment diredly contradicts my experi- 

 ment, on the fuppofition that water is a compound body; but 

 if examined upon my fuppofilion, that the acids are neceflary 

 in forming the gafes, and that the water is only neceflary in 

 forming the water of compofiiion, I hope I (iiall be able to 

 prove tliat his experim(int confirms my opinion. There were 

 very little of gales formed by this experiment, and the wires 

 were very much calcined; now this calcination v\as from the 

 acid, or acids, I proved by repeating the very fame experi- 

 ments; but only inftead of diftilled water, I ufed a folution 

 of potafh, and inftead of the wires being calcined, they were 

 not fenfibly afled upon, and the potafli became nitrated. — 

 Now, Mr. Nicholfon, I (ferioufly and ardently) call upon 

 your numerous readers to perform this experiment, which 

 I think muft be decifive. 



I can but fmile at the French chemifts, in making the pro- 

 portion of the gafes fo exactly to tally witli their opinion of 

 the compofition of water ; but I have in my experiments found 

 very difterent refiilts; the kind of gcu'es depending a good deal 

 ppon the wires ufed, the different metals, their length, and 



(he 



