570 



Miss D. J. Lloyd. 



014 molecular sucrose.* There is a rapid intake of water followed by loss, 

 the weight often falling much below the initial weight. This curve should be 

 compared with the curve of change of weight in hypotonic (010 molecular) 

 •Ringer, given in fig. 2. 



The curve characteristic of a concentration higher than 27 molecular is 



140 



120 



100 



5 firs. 



Fig. 2. 



also given in fig. 1. The initial intake not only is not present but is not 

 even represented by a variation in the rate of loss. The relation throughout 

 is simply linear. 



The fact that the loss of weight in the more concentrated solutions is in 

 linear relation to time is of interest. The osmotic equivalent of an untreated 

 muscle exposed to a solution such that it takes in water, clearly undergoes a 

 change since the intake gives place to a loss in weight usually greater than the 

 previous gain. Does the osmotic equivalent of the surviving muscle 

 spontaneously change or is the change just mentioned due to the exposure to 

 a hypotonic solution ? The linear form of the curve of loss in a hypertonic 

 solution suggests that the variation of state is due to the influence of the 

 solution. The linear form of the curve also would imply that the loss is due 

 to a change in the state of the muscle, for if it were merely the establishment 

 of an osmotic balance with a fixed effective mass of solute within the 

 muscle, the rate would diminish as the effective concentration within the 

 muscle approached that outside it. Both above and below a certain concen- 

 tration the progress of change bears the character, not of the simple establish- 

 ment of osmotic equilibrium between two solutions initially of different con- 

 centration, but of the response of a labile system to an external change of 

 state. 



* It must be remembered that a 0'125 molecular solution of sodium chloride (taken 

 by most writers as isotonic) is osmotically equivalent to a - 23 molecular solution of a 

 •sugar. 



