120 Chemical EffeBs of Galvanic Experiments. 



P. S. I beg leave to requeft; that an error of the prefs in the paper on Ventilators, nl4y 

 be cOrre£led, page 7, line \6 and 17, for "and this way of ufing it might be made" 

 read " and^r this way of ufing it, it might be made." 1 



I alfo will thank you to notice, that my ventilator was conftrufted in March 1 798, be- 

 fore Venturi's book came to England, which I underftand was in November 1798. Mr. 

 Bonnycaftle, of Woolwich, to whom I fhewed it, afid its mode of aftion at that time, can 

 no doubt recolleft this circumftance. 



J. W. B. 



V. 



Oh the Chemical ABion of the different Metals upon each other at the common Temperature of 

 ike AlmofpherCi and upon the Explanation of certain Galvanic Phenomena, By M, 

 Fabbroni*. 



T. 



HE phenomenon fpoken of by Sultzer, in his Theoriedes Plaijirs-, published in 1767, 

 has been clafled among galvanic phenomena, that is to fay, the myflerious fenfation which 

 is manifefted on the tongue by the contact of two metals in mutual contaft, which would 

 have excited none if they had been feparately applied to that organ. In fait, I have been 

 perfuaded, that this very principle which produces an unexpefted tafte in this cafe, may 

 alfo produce a convulfive coatradlion in the animal fibre, when it comes to touch the irri- 

 table and fenfible parts uncovered at the fame time. But fo far from attributing thefe 

 cffefts with all the world to an agent almoft unknown, fuch as the eleitric fire, I imme- 

 diately fuppofed them to depend upon a mere chemical operation, in the fame manner as 

 probably the fenfe of tafle itfelf is produced, which renders the mechanifm much more 

 intelligible. I made reflections, and inftituted experiments on this curious fubjeft, of 

 which I gave an account to the Academy of Florence in 1792. The volume has not yet 

 been printed ; but I think the fubjeft is fpoken of by Brugnatelli in his Journal. I have 

 neither his abridgment, nor my own memoir at hand; I fliall therefore repeat in this place 

 nothing but what remains clearly in my recollection. 



I had before obferved on many occafion?, that running mercury retains its metallic 

 fplendor a long time while alone and uncombined ; but that its amalgam with any other 

 metal whatever is foon tarnifhed or oxided, and increafes in weight in proportion to that 

 progrefTive change. 



I have kept, for many years, fine tin without any alteration in its argentine appearance, 

 but this was not the cafe with regard to the different alloys I had made with the fame 

 metal for economical fpeculations. 



* Tranflated from the Journal de Phyfique VI. new Series, p. 34*. 



I had 

 3 



