iv ELECTROMOTIVE ACTION IN MUSCLE 357 



for the same time into nitric acid (yoVo)' tna ^ tne wat er has a 

 quicker destructive action than the dilute acid, and du Bois- 

 Reymond states that a gastrocnemius clipping into distilled 

 water (15 C.) was death-rigored and acid within an hour. 

 Consequently one might have expected, if the development -of 

 current in a " parelectronomic " muscle depended only upon the 

 destruction of a particular layer at the natural cross-section, that 

 on moistening it with distilled water, a powerful, normal current 

 would in a short time be apparent, since it is proved by experi- 

 ence that the current - developing property of a fluid is quite 

 independent of its conductivity. This is partly contradicted 

 already in the experiments of du Bois - Eeymond, since the 

 development of current in parelectronomic muscles, on dipping 

 them into distilled water, proceeds weakly and sluggishly. The 

 sartorius reacts even better. If the knee-end dips into water, 

 an increase of volume is perceived in it shortly after, and it will 

 then regularly be found weakly positive to points of the normal 

 surface. After longer duration of the action of water (20 

 40 minutes) the muscle section is much swelled, and double its 

 former breadth ; it looks very dark, and exhibits all the external 

 signs of rigor. At the same time the partially rigored muscle 

 shows as little electromotive action as before, or there may still 

 later be weak signs of a normal demarcation current. Even after 

 hours of the action of distilled water, the demonstrable P.D. of 

 the two sections of the muscle is, in spite of the marked differ- 

 ences in their physical properties, relatively insignificant, and 

 not to be compared with those which underlie the normal 

 demarcation current between longitudinal surface and artificial 

 cross-section (18). 



When we remember that all known methods which throw 

 the contractile substance of the muscle into rigor (heating to 

 40 C., treatment with chloroform, acids, etc.), produce power- 

 ful demarcation currents on local application, the absence of 

 electromotive action in the partially water - rigored sartorius 

 is very significant, since it would appear not to harmonise with 

 a chemical theory of the muscle current. In opposition to this 

 it must be remembered that the condition of " water - rigor " 

 cannot be immediately identified with the deep-seated chemical 

 alteration of the muscle -substance, due to spontaneous or sus- 

 tained rigor, or to heat-rigor. This, because on the one hand 



