Prof. Majocchi on the Origin of the Voltaic Current. 97 



from which the solution of most of the equations considered 

 by Mr. Bronwin will obviously follow. There are however 

 various other cases in which the general solution is interpre- 

 table. 



I remain, Gentlemen, 



Your obedient Servant, 

 Lincoln, Jan. 1, 1847. George Boole. 



XXI. Observations and Experiments respecting the Origin 

 of the Voltaic Current. By Professor Gianalessanduo 

 Majocchi*. 



A FTER the discussion which took place in the last sittings, 

 and principally in that of yesterday, respecting the origin 

 of voltaic electricity, among some of our distinguished phy- 

 sicists, and particularly between the illustrious president of 

 the section Prof Orioli and Prof. Botto, I have been induced 

 to extract the following paper from an essay of mine on the 

 same subject. 



At the Turin Congress in 184.0, the question of the two 

 theories, the chemical and that o'i contact, was agitated, with a 

 view to explain the origin of voltaic electricity. There is no 

 doubt that where a chemical action takes place, there is also a 

 development of electricity; but the fluid which becomes free 

 requires certain conditions to form a current. In like manner 

 it is certain that, on placing two heterogeneous bodies in con- 

 tact, there is a development of electricity ; and in this precisely 

 consist the fundamental facts which led Volta to the discovery 

 of his pile; and on the same principle is founded the in- 

 genious apparatus of insulating plates, armed with leaves of 

 heterogeneous metals, which our colleague Prof. Marianini 

 exhibited at the Congress of Turin, and which, variously 

 arranged, he yesterday showed to this assemblyf. The che- 

 mico-electricians maintain that the fundamental facts of Volta 

 dejiend on the chemical action upon the metal, produced by 

 the moisture of the hand, of the air, &c. ; but the careful ex- 

 periments instituted by Marianini, Pfaff; Belli, Peltier, and 

 some other physicists, appear, in the development of electri- 



* Translated froai the Annali di Fisica, Chimica e Mateniatiche, and 

 communicated by the Author. 



The chief portion of this paper was read by the author at the Congress 

 of Milan, Sept. 27, 1844. See Annali, t. xvi. p. 120; and Atli dclla^csla 

 Kiumone dcgti Scicnziali Italiani, p. 118-119. 



n,t '*^ '" ^''^"•^'ooed in his work Mcmnrk di Fisica sperimentalc, Modena, 

 1838, and in another work printed at Modena under the same title in 184l! 

 in which is contained the Mcmorie sui coihenti armati die si caricano da si 

 col mutuo conlatlo d" un annalura coll' ultra. 



