162 



MATHEMATICAL AND PHYSICAL SCIENCE. 



[Diss, VI. 



(733.) Of these two very opposite aspects of this remark- 

 able experiment, it might have been reasonably enough 

 anticipated, that one should be wholly erroneous. 

 This, however, is not the case. Galvani was justified 

 in both his inferences, although he unquestionably 

 believed that only one could be true. As a physio- 

 logical anatomist, he not unnaturally adhered finally 

 to the opinion of vital or animal electricity being the 

 cause of the phenomenon which he had observed. Vol- 

 ta, on the other hand, already an experienced natural 

 philosopher, though for a short time an entire con- 

 vert to Galvani's published opinions, maintained the 

 contact of metals, unlike either in kind or in their 

 mechanical condition, to be the source of the nervous 

 commotion ; and whilst he was enabled to support his 

 opinion by very striking experiments, its popularity 

 was not unjustly perhaps exalted to the highest pitch 

 by the happy application which he made of it, to the 

 construction of that wonderful instrument, the vol- 

 taic battery, which effectually withdrew attention for a 

 time from the comparatively feeble and obscure effects 

 of the electric power residing in the animal tissues. 

 (731.) The historian of science, well aware how far the in- 

 electricity* *" ns ^ c importance of discoveries is from depending 

 of the frog, upon the mere magnitude of their effects, and how 

 often the philosopher, dazzled by the splendour of a 

 new truth, overlooks some minute concomitant phe- 

 nomenon which hereafter may rival or eclipse its 

 splendour, readily recognises the perseverance with 

 which Galvani maintained his theory of animal elec- 

 tricity as a part of the true philosophical character, 

 and therefore as enhancing his reputation. The 

 metallic arc which, by connecting the muscular part 

 of the limb with the root of the lumbar nerve, occa- 

 sioned the convulsion, was to be regarded, on his 

 theory, as merely establishing equilibrium between 

 those parts to which the vital principle had commu- 

 nicated an electric tension similar to that which sub- 

 sists on the opposite surfaces of a charged plaie or 

 Leyden jar. Galvani gradually disembarassed his ex- 

 periments from the suspicious presence of metals alto- 

 gether. Taking the prepared hind-limb of a frog, 

 with the connected nerve entering the spine, he found 

 that when the latter was suffered simply to touch the 

 bare surface of any muscular part, and without the 

 Confirmed intervention of metal or any other conductor, a spasm 

 A von n ^ *^ e ^ m ^ inwnediately occurred. 1 This important 

 Humboldt. experiment was repeated and varied in 1795, by the 

 celebrated Baron Alexander von Humboldt, who pub- 

 lished a paper on the subject in Gren's Journal, fully 

 confirming Galvani's conclusions. Volta, on the other 

 hand, admitting the facts, strove to explain them on 

 the supposition, that they were due, like other electric 

 currents, merely to the heterogeneous nature of two 

 solid bodies, the muscle and the nerve brought into 

 opposition, and moistened by a conducting liquid. 



Experiments instituted after a lapse of 30 years, with 

 the aid of new instruments, and vastly increased know- 

 ledge of electric manifestations, have conclusively de- 

 monstrated the accuracy in this respect of Galvani's 

 reasoning in preference to Volta's. 



The publication of the results already noticed did (735.) 

 not take place till 1791 in his celebrated paper in the Gradual 

 Bolognese Transactions, The statement popularly G 

 made by almost every writer (and which may be views, 

 traced to Alibert, one of the earliest historians of the 

 subject, but whose authority seems to be of little 

 weight), is that the discovery of Galvanism was made 

 in 1790, in Madame Galvani's kitchen, where a frog 

 soup was being prepared for that lady's repast, she 

 being at the time in delicate health. The absurdity 

 of the invention is evident from the history which 

 we have given, founded on unquestionable documents. 

 The memoir of 1791 was the resume of elaborate ex- 

 periments continued with (apparently) little inter- 

 ruption for eleven years ; and the most interesting 

 results had been digested in a Latin tract Jive years 

 before. All this shows at once great patience and 

 intelligence on the part of Galvani, who, perceiving 

 the difficulty and also the probable importance of 

 the subject (in a physiological view) oscillating per- 

 haps in some measure between the two very opposite 

 opinions regarding the source of muscular excitement 

 which we have seen that he almost simultaneously 

 held, postponed for so long a time the publication of 

 a discovery which he must have been sure would con- 

 fer upon him a great reputation. By the time of his 

 publication his views had become fixed in favour of 

 animal electricity ; and he defended it in several suc- 

 ceeding memoirs. 



The unjust deposition of Galvani from his chair on (736.) 

 political grounds affected seriously his health and His death, 

 energies. Perhaps his latest experiments were on the 

 Electricity of the Torpedo. He died 4th December 

 1798, aged only 61 happy perhaps in not having 

 witnessed the discovery of the Pile, which, by its as- 

 tonishing results, was to throw into the shade Gal- 

 vani's more intricate and difficult studies. 



To appreciate justly Galvani's place in scientific (737.) 

 history, we must recollect three circumstances which His distil 

 have often been overlooked, First,th&ihis discoveries S l 

 were the result of patient, ingenious, and protracted 

 research, not of a casual observation exciting ignorant 

 surprise. Secondly, That however deficient was Gal- 

 vani's theory of animal electricity to explain all, 

 or even the most conspicuous facts witnessed by him, 

 it was a real discovery which has been confirmed by 

 the latest and most scrupulous researches, and of a 

 physiological importance which can hardly be over- 

 rated. Thirdly, Galvani's Commentary was received 

 at the time with enthusiasm, not only from the im- 

 portance of the facts which it contained, but from the 



1 The earliest notice of this result is found in one of Galvani's autograph MSS., which appears certainly to date from 1786, 

 Rapporto, p. 48, 18. 



