98 INJURY, RECOVERY, AND DEATH 



easily be overlooked except in cases where recovery can be 

 measured with considerable accuracy, and it seems 

 possible that further investigation may show that incom- 

 plete recovery is a general phenomenon. 



Let us now consider the cause of permanent injury. 

 If we assume that the death process proceeds according 

 to the scheme 



it is evident that in sea water A must be continually 

 renewed. Let us assume that this occurs by means of 

 the reactions >S > A and that (the origin of all 

 the substances produced) is present in such large amount 

 that its concentration does not appreciably change dur- 

 ing the time of the experiment. If we start with alone, 

 it will produce all the other substances according to 

 the scheme 



and their amounts will increase until equilibrium is 

 reached, i. e., until they are decomposed as rapidly as they 

 are formed. Their values will then remain constant. 



We assume that when the tissue is placed in NaCl 

 0.52 Mj the reactions ** S >A cease, while the reac- 

 tions A >M^ _ B continue. In consequence the values 

 of A, Mj and B steadily fall. If the tissue is now replaced 

 in sea water the reactions >$ >A recommence and 

 in consequence the values of A, M, and B will rise to their 

 original level (the level which is normal for sea water). 

 But if is diminished by exposure to the solution of NaCl 

 it can no longer restore these values to their original level. 

 If, for example, it diminishes to one-half it can restore 

 them only to one-half the normal values. In this case the 

 permanent injury would amount to 50%. We therefore 



