PRESENT STATE OF ORGANIC ELECTRICITY. 325 



An artificial transverse section is a section made at right 

 angles to the fibres. 



The natural or artificial extremities of fibres are transverse 

 sections. 



By employing a very delicate galvanometer, and by certain 

 refined precautions in the arrangement of his experiments, 

 Du Bois Eeymond found that the longitudinal section, natural 

 or artificial, is invariably positive in relation to the natural 

 or artificial transverse section. The following are the general 

 laws of the derived muscular current. 



1. If any point of the natural or artificial longitudinal 

 section be put into connection, by means of the galvanometer, 

 with any point of the natural or artificial transverse section, 

 the needle will indicate a current in the wire from the longi- 

 tudinal to the transverse section. 



2. If one point of the natural or artificial transverse section 

 of a muscle is brought into connection with another point of 

 the same or of another similar transverse section, and if the 

 points be unequally distant from the centre of the section 

 considered as the base of a muscular cylinder, a current is 

 indicated passing from the electrode furthest from the centre, 

 and directed to that which is nearest to it. 



3. If we now consider the mass of the muscle as a cylinder, 

 and connect a point of the natural or artificial longitudinal 

 section nearer the middle transverse section of the mass, with 

 a point of the natural or artificial longitudinal section more 

 distant from the middle, a current is indicated passing from 

 the nearer to the more distant point. 



4. If both connected points of one or of two natural or 

 artificial transverse sections be equally distant from the centre 

 of the surface, no current is indicated. So also in regard to 

 longitudinal sections, points equally distant from the middle 

 produced no current. 



These laws are most satisfactorily illustrated in the muscles 



