Vital and Physical Motion. 1 3 3 



Six years later, in a chapter of his classical work on 

 comparative anatomy,* Professor Duges, of Montpellier, 

 argues with much clearness that all organic tissues are 

 the seat of two opposite movements expansion and 

 contraction and that ' la contraction musculaire ne con- 

 siste que dans 1'annihilation de 1'expansion.' The muscle 

 is supposed to contract in virtue of its elasticity, just as 

 a piece of caoutchouc might contract when set free from 

 a previous state of extension ; and an analogy is hinted 

 at between the expanded state of the muscle and the 

 fluid state of the fibrine of the blood, and between rigor 

 mortis and the coagulated state of this fibrine. Analo- 

 gous in its effects to electricity, the vital agent is sup- 

 posed to accumulate in the muscles, and to produce 

 expansion by causing the muscular molecules to repel 

 each other ; and contraction is supposed to be brought 

 about either by the sudden discharge (as in ordinary con- 

 traction) or by the gradual dying out (as in rigor mortis) 

 of the vital agent. And, further, it is supposed that the 

 rhythmical movements of muscle are caused by succes- 

 sive discharges of the vital agent, which discharges are 

 brought about whenever this agent acquires a certain 

 degree of tension ; and that the cramps of cholera, or 

 the spasms of tetanus or hysteria, are consequent upon 

 the development of the vital agent being for the time 

 suspended. 



More recently still, namely in 1847, Professor Mat- 

 teucci communicated a paper to the Parisian Academy 

 of Sciences! upon the influence of the nervous fluid in 

 muscular action, in which he writes : ' Ce fluide d6- 

 veloppe principalement dans les muscles, s'y repand, et, 



* " Traite de Physiologic comparee de 1'Homme et des Animaux." 

 8vo. Montpellier and Paris. 1838. 



f "Comptes Rendus." March 17, 1847. 



