50 ABSORPTION AND RETENTION OF POTASSIUM 



tried with determinations of water as well as potassium in the muscles. 

 After perfusing 200 cc. of a potassium-free Ringer solution through 

 both legs, one leg, was tied off and 800 cc. were then perfused in the 

 course of 8 hours through the other leg. The gastrocnemius of the 

 slightly perfused leg yielded 0.304 per cent of potassium and the 

 same muscle of the other leg 0,267 per cent; but the first of these 

 muscles contained 18.85 per cent of solids while the second had only 

 16.7 per cent, so that the slightly perfused muscle contained 1.61 

 per cent of potassium in its solids and the more extensively perfused 

 one had 1.60 per cent of the solid matter. The average content of 

 potassium in the solids of the fresh muscle is 1.75 per cent, .so that 

 muscles of both legs had doubtless lost some potassium. These 

 experiments were done before the extent of variability in water and 

 potassium content of muscles of different frogs was fully appreciated. 

 In a further series samples of the gastrocnemius of one leg were taken 

 after a brief perfusion, lasting less than 10 minutes, sufficient to 

 remove all visible blood. The muscles of the other leg were then 

 perfused during a suitable period and samples of both gastrocnemii, 

 after vacuum desiccation to constant weight, were used entire for 

 wet ashing and potassium titration. The effect on the perfused 

 muscle was then computed as the percentage loss of the original 

 potassium content as shown by the muscle that was not perfused. 

 Such experiments gave consistent results and showed, as set 

 forth in Table III, a loss of potassium during early stages of 

 perfusion with the limit of potassium loss approached after 5 hours. 

 Subsequently little or no loss of potassium occurs. The time of 

 perfusion showed more consistent relation to potassium loss than did 

 the amount of perfusion solution used. This indicates diffusion of 

 potassium from the muscle cells into the fluid of the lymph spaces 

 irrespective of considerable change in the rate at which the latter is 

 replaced. Such a result may be explained by the fact that in any case 

 the perfusion solution, present in such quantities as to greatly distend 

 the lymph spaces, would be notably lower in potassium content 

 than the intracellular fluid. 



The relation of muscular activity to loss of potassium from the 

 muscle cells was sought in the following experiment. Potassium-free 

 Ringer solution was perfused through both legs during 2 hours. 



