691 



It would appear, also, (in so far as electrical action is concerned) 

 that there is a close agreement between ordinary muscular contrac- 

 tion and rigor mortis,, for in ordinary muscular contraction, as Prof. 

 Du Bois Reymond has so well shown, there is a partial disappearance 

 of electrical action. Professor Matteucci, however, is doubtful as to 

 this, and he maintains, on the contrary, that at this time the " mus- 

 cular current" is sometimes reversed, and sometimes increased in 

 intensity without being reversed. 



In his recent experiments Prof. Matteucci uses a galvanometer of 

 which the ends are so arranged as to get rid of the disturbing 

 influences of secondary polarity. Instead of being of platinum 

 immersed in a saturated solution of common salt, as in Prof. Du Bois 

 Reymond' s arrangement, these ends are of amalgamated zinc im- 

 mersed in saturated solution of neutral sulphate of zinc. This 

 arrangement, originally proposed by Dr. Jules Regnault, the author 

 agrees with Prof. Matteucci in regarding as a great improvement 

 upon that used by Prof. Du Bois Reymond ; for, says he, " not 

 only is the disturbing influence of secondary polarity got rid of, 

 but the entrance of currents into the coil of the galvanometer is 

 greatly facilitated. Of this I am satisfied after many comparative 

 trials*." 



In the experiment in which Prof. Matteucci finds what he con- 

 siders to be the proof of the reversal of the muscular current during 

 contraction, he takes a prepared frog's thigh with a long portion of 

 nerve attached, and watches the changes of the muscular current 



* The galvanometer used by Dr. Radcliffe was made by Mr. Becker, then of New- 

 man Court, after the pattern of the one used by Prof. Du Bois Reymond. The 

 gauge of the wire forming the coil is No. 38, or as nearly as possible that of the 

 pattern coil ; the weight of the wire entering into the coil lib. lloz., the layers of 

 the coil 154, the number of coilings 20,020, and upwards of three English miles. 

 The needles are cylindrical, with each end sharpened out into a long point, and 

 the connecting piece, instead of being made of tortoiseshell, as in Du Bois 

 Reymond's instrument, is made of aluminium a difference by which the astatic 

 system becomes a little lighter, namely, 4'5 grains instead of 4*9 grains. In the 

 first instance, Dr. Radcliffe used electrodes consisting of a pair of platinum plates 

 immersed in a saturated solution of common salt (an arrangement recommended 

 by Du Bois Reymond) ; afterwards he used the electrodes recommended by 

 Dr. Jules Regnault, and adopted by Prof. Matteucci electrodes consisting of a 

 pair of amalgamated zinc plates immersed in a saturated solution of neutral 

 sulphate of zinc. 



VOL. IX. 3 A 



