360 ELECTRO-PHYSIOLOGY CHAP. 



the fact that an electrical theory of muscular contraction was 

 founded by Prevost upon certain observations of Ampere, as 

 early as 1837, and this is of interest, inasmuch as it shows 

 to what extent physiological conceptions may be influenced 

 by current physical theories. Prevost convinced himself by 

 microscopic investigation that the cross-striation of the fibres 

 of skeletal muscle was simply the optical expression of looped 

 nerve-endings lying parallel with one another, which pull in 

 opposite ways at the moment when an electrical current 

 traverses the entire system of loops in the same direction. In 

 order to demonstrate this current, Prevost introduced a " very 

 fine non-magnetic needle into the frog's leg in the direction of 

 the fibres ; the point projected, and was covered with iron- 

 filings " ; at the moment at which a vigorous contraction was 

 produced by injury to the spinal cord, the iron - filings were 

 said to arrange themselves round the point of the needle, as if 

 they had been magnetised. A similar theory was advanced by 

 Wharton Jones in 1844 (du Bois, I.e. p. 10). "According to 

 his view, which follows on with Bowman's observations (com- 

 position of muscle-fibres out of ' discs '), the muscle-fibres consist 

 of discs arranged in columns, or rouleaux, connected by a flexible 

 and elastic substance, which enable them to approximate, or 

 recede from one another. The discs, according to TVharton 

 Jones, are converted by the influence of the nerve into electro- 

 magnets, and their antagonistic traction produces the shortening 

 of the muscle. The electro -magnets (" appareils nervo-mag- 

 netiques ") are not indeed surrounded on all sides by nerves, as 

 an iron magnet' would 1 >e with copper wire ; this only proves, 

 however, that nature adapts itself to simpler arrangements. 

 The first real advance in this department is once more owing to 

 that indefatigable worker who discovered the muscle current 

 almost simultaneously with du Bois - Pieymond. C. Matteucci, 

 after taking infinite pains, from 1838, to demonstrate electrical 

 action during muscular activity, and repeating inter alia the 

 experiments of Prevost in different forms, succeeded at last 

 in discovering a fact which gave the required determination. 

 ( >n February 28, 1842, Matteucci communicated to the Paris 

 Academy the account of an experiment which must be reckoned 

 among the most elegant and interesting in experimental physio- 

 l<"4y. This was proof of what du Bois-Eeymond afterwards 



