438 On the Electromotive Properties of Muscle. [Dec. 14^ 



manner directed, it appears that it possesses properties entirely incon- 

 sistent with the " law of the muscle-current " in the following re- 

 spects : — 



(1) That the electrical tensions of the upper and lower cut surfaces, 

 instead of being identical, differ widely ; 



(2) That the equatorial zone of the natural surface presents none of 

 the properties assigned to it by the " law " ; 



(3) That the excitatory yariation is not in conformity "with the " law." 



8. On the ground of these experiments I conclude that in the gastro- 

 cnemius of the frog the part nearest the tendon is (in the natural state) 

 negative to the opposite end, and from the investigation of other muscles 

 of the limbs I infer that in them the distribution of electrical tension 

 on the natural surface is governed by a similar law. I have further 

 shown that the phenomenon hitherto known to physiologists as the 

 " negative variation " cannot be described as " diminution of a previ- 

 ously existing current " between cut and natural surface, but may, in 

 all its phases, be completely explained as a temporary diminution of the 

 electromotive force of those parts of the muscle which are in the natural 

 state negative as compared with the electrically inactive tissues of the 

 body of the animal ; and, as a direct consequence of this, that the excita- 

 tory variation of animal muscle is opposed in sign to that of the excito- 

 contractile tissue of Dioiicea. 



9. This being understood, all that is observed in the muscle-cylinder 

 can be explained as resulting from the properties exhibited by the muscle 

 itself before its mutilation ; so that it is not only true that the general 

 properties of the cylinder can be deduced from those of the muscle as a 

 whole, but that (as the Tables show) the special peculiarities of each 

 particular case may be accurately foretold if the whole organ has before 

 been investigated. 



Table I. — Showing the Eesults of Observations as to the Electromotive 

 Properties of Eight Oastrocnemius Muscles. 



Muscle. 



Length. 



of 

 muscle 



in 

 eentm. 



Zone of greatest negativity. 



Zone of greatest 

 positivity. 



Ten- 

 don. 



Insid 

 of 



skin 



&c. 



close 

 to tei 



don, 



Muscle in situ. 



Muscle detached. 



Dis- 

 tance 

 from 

 ; inser- 

 tion. 



Poten- 

 tial. 



Vari- 

 ation. 



Dis- 

 tance 

 from 

 inser- 

 tion. 



Potential. 



Varia- 

 tion. 



Dis- 

 tance 

 i from 

 inser- 

 tion. 



Potential. 



Variation. 



Frog 1 : 



















-1-6 











4-2 



1-9 



-4-7 



+ 1-7 



! 



— 5'5 



-4-0 



3-8 











I 



4-2 



2-2 



-6-2 



+ 2-3 



2-0 



-5-3 



-4-8 



4-0 



-FO-5 







-2-6 



-2- 



Frog 2: 



























G-astr. r 



4-2 



1-6 



-4-8 



+ 3-2 



1 1-2 



Above -8-0 



-6-0 (cir.) 



4-2 



-)-0-0 







-2-6 



-2- 



„ I 



4-2 



1-4 



—4-0 



+ 1-4 



1 1-7 



-5-0 



-5-0 



4-1 



+0-6 







-1-4 



-r 



Frog 3: 



























Gastr. r . . . 



3-6 



1.5 



-8-0 (cir.) 



-3-0 



1-5 



Above —8-0 



-3-0 (cir.) 



3.5 



-1-0 



-0-6? 



-4-7 



-4 



I 



3-6 



f3 



— 5-5 



-2-5 



0-6 



8-0 (cir.) 



3"5 



3-5 



-0-3 







-4-0 



-4- 



Frog 4 : 

















O'O 









G-astr. r 



3-4 



1-5 



-1-7 



-0-8 



1-5 



,3-7 



2-0 



3-4 











„ I 



3-4 



1-4 



-3-6 



-1-5 



0-9 



4-9 



2.5 



3-4 



0-0 





-2-3 



-2- 



