Carbon Dioxide of Injury in Nervous Tissue. 37 



rate, which, in turn, after a few readings, falls to the former low 

 rate. The following determinations on a pair of frog sciatic nerves 

 shows this fact. 



Time. Rate. 

 Fresh, first reading 360 seconds .28 

 " second " 1440 " .07 

 Crushed first " 420 " .24 



" second " 1740 " .06 



Rate = 



roo 

 Time 



It is apparent that the acid resulting from injury develops only 

 momentarily and is soon washed out by the surrounding neutral 

 Ringer's solution. It therefore seems reasonable to suppose that 

 the carbon dioxide output during the time following is largely that 

 of respiration. 



1. 2 3 1 



HOURS 



Fig. 2. 



With a view to comparing the rates of acid production of 

 central nervous system, muscle and nerve fiber, equal weights of 

 the medulla, the sartorius muscle, and the sciatic nerves of the 



