26 ANIMAL ELECTRICITY. LECTURE I. 



3. Deir uso e dell' attivita dell' arco conduttore nelle con- 



trazioni dei muscoli. Anonymous. Bologna, 1794. 



4. Do., Supplemento. Bologna? 1794. 



The two representative experiments are : — 



1. The contraction with metals. 



2. The contraction without metals. 



The principal difference between Galvani and Volta was 

 that according to the former the contraction with metals in 

 the circuit, was due to animal electricity conducted by the 

 metal, while according to the latter it was due to an excita- 

 tion by ordinary electricity aroused by contact of dissimilar 

 metals. The contraction with metals did not prove the 

 existence of animal electricity. This could only be done by 

 an experiment in which none but animal tissues were in 

 circuit. Thus the origin of "Animal Electricity" becomes 

 fixed at the " contraction without metals." 



This experiment is first mentioned in the anonymous 

 Trattato of 1794, not in Galvani's Commentary of 1791. 



Who was the author of the anonymous " Trattato," and 

 who therefore was the author of the " Contraction without 

 metals"? Aldini in his "Essai sur le Galvanisme " alludes to 

 the experiment as his own. But there is nothing to indicate 

 whether Aldini or Galvani was the author of the Trattato. 



On the other hand, Gerhardi in his annotations to the 

 " Opere edite ed inedite del Professore Luigi Galvani," 

 Bologna, 1841, and Du Bois-Reymond in his " Thierische 

 Elektricitat," unhesitatingly attribute the anonymous Trattato, 

 including the important experiment, to Galvani alone as the 

 " vero ed unico autore." 



The manuscript of this Trattato, said by du Bois- 

 Reymond to be preserved at the University Library of 

 Bologna, and to be partly in Galvani's handwriting and 

 partly in another's handwriting, is not now to be found. 

 With regard to this, we are therefore thrown back upon 

 probabilities, and these in my opinion, indicate at least a joint 

 authorship of the Trattato, certainly not the exclusive author- 

 ship of Galvani, and certainly not a plagiarism by Aldini. 



