ELECTRO-PHYSIOLOGY. 



591 



current passes along the conductor from the point nearer the center 

 to the one farther off. The reverse is the case for the transverse. 



3. When two points are connected on the same or on opposed 

 surfaces equally distant from the center, or when the centers of two 

 opposite surfaces are joined, there is no movement of the needle of 

 the galvanometer. 



The parelectronomic part of the muscle is the tendinous part of 

 the muscle, which is negative instead of being positive, as is the rule. 

 Here it is necessary to make an artificial section for the purpose of 

 demonstrating the electrical phenomena of muscle. 



Fig. 227. Schema Representing the Inequalities of Electric Ten- 

 sions upon the Natural Longitudinal Surface and upon the Artificial 

 Transverse Surface of a Muscle-cylinder. Also the direction of the 

 electric currents from the exterior to the interior of the muscle. (LA- 

 HOUSSE. ) 



Hermann has shown that the muscle-currents (demarcation cur- 



ts) are the result of the preparation, and do not exist in the nor- 



1, intact fibers when in a state of repose. These galvanometrical 



viations are due to the traumatic action of air, cold, or chemicals. 



Electrical Phenomena of Contracting Muscle. If upon the elec- 



es connecting the poles of the galvanometer a muscle is so placed 

 at the needle deflects, then on tetanizing the muscle by stimulat- 



its nerve, the needle will be seen to retrace its movement of 

 ection. This reverse of the natural current is known as negative 

 viation. This has been shown to be due to a weakening of the 

 tural muscle-current, and not to the production of a new one con- 



