The Relation of Excised Muscle to Acids, Salts, and Bases. 283 



lithium, and aranionium solutions, and fleeting in the calcium and barium 

 solutions. The behaviour of the muscle in sodium solutions is in strong 



/so T 



Fig. 5. 



Abscissae = time in hours from beginning of experiment. 



Ordinates = weight of muscle expressed in percentage of initial weight. 



contrast to its behaviour in the presence of any other single salt, and 

 combined with this is the well-known fact that isotonic sodium solutions are 

 far less toxic for excised muscles than solutions of any other single salt. 

 The behaviour of an excised muscle in 0*125 molecular sodium chloride is 

 mainly determined by its initial state. It may show a rise in weight, or it 

 may remain unchanged for several hours, but in either case the time-weight 

 curve runs for a considerable time parallel to the X axis. Two curves for 

 0*125 molecular sodium chloride are shown in fig. 5. It might be noted 

 that the Y-axis in fig. 5 is drawn on a different scale to the Y-axis in the 

 other figures. The curves given in fig. 5 are taken from actual experimental 

 results. It should be noted that they represent the mean of measurements 

 which differ from each other somewhat widely. 



To turn now to the consideration of the time-weight curves in the case of 

 alkaline solutions — in dilute alkalies, the curve first rises, then falls abruptly 

 for a few minutes, then rises again to a maximum. These curves are shown 

 in fig. 4 for 0*001 normal and 0*002 normal caustic soda. 



In dilute alkaline solutions the fall between the two maxima is very clear ; 

 as the alkalinity of the solutions is increased, it gets partially obliterated, 

 till it becomes merely a notch in the curve, and, at 0*1 normal, can no 

 longer be distinguished. 



VOL. LXXXIX. — B. 2 A 



