184 



IRRITABILITY 



recognized as manifestation of the prolonged refractory period 

 nor as fatigue. A further advance was made by the investigations 

 of Thorner. He placed two nerves of the same frog in a double 

 chamber under completely identical conditions with the excep- 

 tion that one remained in a state of rest, whilst to the other 

 tetanic stimuli were applied. (Figure 35.) If this took place in 





Fig. 35. 



Double glass chamber for comparative experiments on 

 fatigue of the nerve (n n). A and B— Wires of 

 the electrodes. (After Thomer.) 



nitrogen, the irritability of the stimulated nerve invariably sank 

 with much greater velocity than that of the nonstimulated, where- 

 as after an introduction of oxygen, even when the stimulation was 

 continuous, both again recovered. In these experiments of 



