ON THE PSYCHO-PHYSICAL VIEW OF NATURE. 475 

 1786, followed, fifteen years after, by Volta's greater 9. 



Animal 



invention. The late eminent Prof. Du Bois-Eeymond, electricity. 

 in various passages l of his scientific and literary writ- 

 ings, has told us of the recurrent fascination which the 

 fata morgana of Electricity has exercised over those 

 interested in the explanation of the phenomena of 

 innervation ; how this seductive clue has been, in the 



1 See vol. ii. pp. 212, 386, 528 of 

 Du Bois - Reymond's 'Reden,' also 

 his ' Untersuchungen iiber thier- 

 ische Electricitat ' (1848), vol. i. 

 pp. 30-128. One of the first to 

 take up in the interests of nervous 

 physiology the clue which Galvani's 

 discovery afforded was A. von 

 Humboldt, who published in 1797. 

 three years before Volta's discovery, 

 his valuable " Versuche iiber die 

 gereizte Muskel- und Nervenfaser, 

 nebst Vermuthungen iiber den 

 chemischen Process des Lebens 

 in der Thier- und Pflanzenwelt. " 

 A lucid account of Humboldt's 

 work is given by Prof. Wundt in 

 the third volume of the German 

 edition of Bruhns' 'Life of Hum- 

 boldt,' p. 301 sqq. "It is diffi- 

 cult," he says, " to picture to 

 oneself nowadays the excitement 

 which the observations of Galvani 

 produced in the scientific world. 

 . . . Such experiments had almost 

 become a general subject of enter- 

 tainment in cultured circles. . . . 

 It almost appeared as if what 

 at that time was looked upon as 

 the most general property of living 

 matter, irritability, were by the 

 experiment of Galvani to be for 

 the first time unveiled in its real 

 essence. ... At the time when 

 Humboldt made his experiments 

 the contest * was still going on 

 between the followers of Galvani 

 and Volta." This referred to a 

 physiological or -purely physical 

 explanation of the phenomenon. 



" Barely three years after the 

 publication of Humboldt's work 

 the discovery of Volta's pile put 

 an abrupt end to all theories 

 which were based upon the phys- 

 iological origin of galvanic phen- 

 omena. The brilliant development 

 of physical galvanism from that 

 moment pushed the physiological 

 aspect of electricity for a long 

 time into the background. . . . 

 Humboldt's work was forgotten " 

 (p. 310). In the meantime Hum- 

 boldt had travelled in South Amer- 

 ica, where he had inter alia 

 observed the " natural electro- 

 motors which stand in such ex- 

 traordinary connection with the 

 nervous system" of the electrical 

 eel (Gymnotus electricus), giving a 

 thrilling description of a battle 

 between the horses and the eels 

 which he witnessed in the waters 

 of Calabozo. (See Humboldt's 

 ' Personal Narrative,' vol. iv. p. 345 

 sqq. ; also ' Ansichten der Natur,' 

 vol. i. p. 33.) Interest in the subject 

 of animal electricity was again re- 

 vived by Italian physiologists about 

 the year 1835. Nobili, Marianini, 

 Santi - Linari, Matteucci repeated 

 and enlarged the experiments of 

 Galvani, and through the influence 

 of Humboldt and Johannes Miiller, 

 the study of the whole subject 

 was comprehensively taken up at 

 Berlin by Du Bois-Reymond about 

 1840, and exhaustively treated in 

 his great work on the subject (vol. 

 i. 1848, vol. ii. 1860). 



