On the Force evolved during Muscular Contraction. 189 



formed. As a manure for growing crops, all experience and all 

 theoretical considerations thei-efore show it to be most valu- 

 able; but when employed to mix with manure heaps which 

 have to stand for considerable periods of time, theory would 

 pronounce, as practice has in many cases done, that its power 

 of retaining ammonia under those circumstances is at the best 

 doubtful. 



XXII. An Experimental Inquiry undertaken with the view of 

 ascertaining lohether any Force is evolved during Muscular 

 Contraction analogous to the Force evolved in the Gymnotus 

 and the Torpedo. By U.Y. Baxter, Escj."^ 



CONVINCED that a calm inquiry after truth is liable to be 

 lost in controversial disputes, we shall just refer in a 

 general note to the principal sources from whence we have been 

 enabled to obtain views such as are confirmed by experimental 

 evidence, and which are now entertained upon the subject of our 

 present inquiry f. 



The fact long since obtained by Matteucci, viz. that of causing 

 the muscles of a galvanoscopic frog to contract by placing its 

 nerve upon the muscles of another animal during their contrac- 

 tion, is well known; and in his last communication J to the 

 Royal Society, Matteucci has adduced strong reasons for believing 

 that an electric disequilibrium is produced during muscular con- 

 traction. 



By means of the galvanometer, Du Bois-Reymond § has satis- 

 factorily shown that an effect occurs upon the needle during 

 muscular contraction. These results have been confirmed by 

 2antedeschi||, Buff^ and Tyndall**. 



* Commuuicated by the Author ; having been read at the Royal Society 

 May 10, 1855. 



t Annates de Chimie et de Pkysicjue, 3'^ serie, vol. xv. p. 64; vol. xxx. 

 pp. 119, 179; vol. xxxix. p. 114. Comptes Rendus, vol. xxviii. pp. 570, 

 641, 653, 663, 782 ; vol. xxx. pp. 349, 406, 479, 512, 563, 699 ; vol. x.xxi. 

 pp. 28, 91, 318; vol. xxxii. p. 131. Bihliotheque Universelle de Genive, 

 Fev. 1850, Juin 1853. On Animal Electricity ; being an Abstract of the 

 Discoveries of Emil du Bois-Reymond, &c., edited by H. Bence Jones, 

 M.D., F.R.S. London : Churchill. 1852. 8vo. Lettre de Charles Mat- 

 teucci a M. H. Bence Jones, F.R.S. Florence : Imprimerie Le Monnier, 

 1853. 8vo. On Signor Carlo Matteucci's Letter to H. Bence Jones, M.D., 

 F.R.S. &c. By Emil du Bois-Reymond. London : Churchill. 1853. 8vo. 



I Philosophical Transactions, 1850. Ninth Series. 

 § Comptes Rendus, vol. x.wiii. p. 641. 



II Bibliotkique Universelle de Geneve, Fev. 1850. H Ibid. 

 ** British and Foreign Medical Review for Jan. 1854, p. 141, 



