W: J. V. OSTERHOUT 



155 



It will be observed that the rate of recovery is approximately the 

 same in all cases ; this applies to the experiments with CaCl2 as well as 

 with those in NaCl. In general it may be said that it usually requires 

 about 60 minutes for the curve to complete nine-tenths of the total 

 rise or fall which occurs in recovery. 



With so large a number of constants it might seem possible to fit 

 any sort of curve and hence the significance of the actual accomplish- 



loo;^' 



■^-, in Cd. CI2 



.S in Ca CI2 



■^-- 



~-x--.. 



'•X 



in Na CI 



S in Na CI 



200 



400 



600 min. 



Fig. 3. Curves showing the values of in NaCl (upper unbroken line) and in 

 CaCl2 (upper dotted line); also the values of S in NaCl (lower unbroken line) 

 and in CaCl2 (lower dotted line). The ordinates give the values of 0; these must 

 be multiplied by 6.75 to obtain the values of S. 



The observed points represent the average of eight or more experiments; 

 probable error of the mean less than 10 per cent of the mean. 



ment might be lessened. This, however, is by no means the case. 

 Moreover, the fixing of one or two constants affects the others in such 

 a way as largely to determine the character of all the curves. 



In the foregoing account many details are necessarily omitted, 

 owing to lack of space. These, however, are not essential to the main 

 purpose, which is to show how the process of injury and recovery may 

 be analyzed and subjected to mathematical treatment. Starting 



