3876.] On the Electromotive Properties of Muscle. 



435 



II. ^' Note on tlie Electromotive Properties of Muscle/^ By J. 

 Burdon-Sanderson^ M.D,_, F.E.S. Received December Q, 

 1876. 



In the great work entitled ' Untersuchungen iiber thierische Electri- 

 citat,' of which the first volume was published by Professor du Bois- 

 Eeymond in 1848, the author promulgated, as the result of the remark- 

 able investigations undertaken by him during the previous six years, 

 certain propositions relating to the electromotive properties of muscle. 

 These propositions (which in the original work were printed in large 

 type) were termed by the author collectively the " Law of the muscle- 

 current," They have been accepted by all later observers as fundamental 

 truths. They are as follows : — 



" The Law of the Muscle-current. I. Active arrangements. A. Strong 

 Currents. If any point of the natural or artificial longitudinal section of 

 a muscle is brought into connexion with any point of the natural or artificial 

 transverse section of the same muscle, so that no tension is thereby pro- 

 duced, a current is indicated by any galvanoscopic apparatus introduced 

 into the inactive conducting circuit, of which the direction in the cir- 

 cuit is from the longitudinal to the transverse section. — B. WeaTc Currents. 

 a. Currents of the transverse section. Eurther, if any point of a natural 

 or artificial transverse section of a muscle is connected in the manner 

 already described Vvdth another point of the same transverse section, or with 

 a point of another natural or artificial transverse section of the same 

 muscle, which we will regard as a cylinder, and if the points are at unequal 

 distances from the centre of the circular area of the transverse section, 

 the galvanoscopic apparatus again indicates a current, though much 

 weaker than the previous one, of which the direction is from the point 

 more distant from the centre to the nearest point. — b. Currents of 

 the longitudinal section. Thirdly, if a point of the natural or arti- 

 ficial longitudinal section, lying nearer to the geometrically central 

 transverse section of the cylinder formed by the muscle, is brought 

 in the same way into relation with a point of the natural or artificial 

 longitudinal section of the same muscle more distant from the central 

 transverse section, the galvanoscopic apparatus again indicates a cur- 

 rent, which is, however, much weaker than that between any point of 

 the natural or artificial longitudinal and any point on the transverse 

 section, but is equal in strength to that between different points on one or 

 two natural or artificial transverse sections. Its direction in the circuit 

 is from the point lying nearer to the middle transverse section to that 

 further removed from it. — II. Inactive arrangements. The galvano- 

 scopic apparatus, on the contrary, remains at rest when two points in 

 one or two natural or artificial transverse sections connected through 

 the inactive conducting circuit are at an equal distance from the centre ; 



