CHAPTER IX 



THE PROCESSES OF DEPRESSION 



Contents: Necessity of cellular physiological analysis of toxic depres- 

 sions by pharmacology. Apparent variety of processes of depression. 

 Depression of oxydative disintegration as the most extended principle 

 in the processes of depression. Asphyxiation, fatigue, heat depres- 

 sion, as a consequence of restriction of oxydative disintegration. 

 Narcosis. Theories of narcosis. The alteration of specific irritability 

 and conductivity in narcosis. Depression of oxydative processes in 

 narcosis. Asphyxiation of living substance when oxygen is present 

 during narcosis. Persistence of anoxydative disintegration in nar- 

 cosis. Increase of the same by stimuli. Depression by narcosis as 

 a form of acute asphyxiation. Hypothesis on the mechanism of 

 depression of oxygen exchange by narcotics. Possibility of com- 

 bining the facts with the observations of Meyer and Overton. 



The processes of excitation of all the effects of stimulation are 

 those which have invariably claimed place in the interest of phys- 

 iologists. The study of the processes of depression, on the other 

 hand, has remained more or less in the background. This is 

 readily understood when it is considered how much more apparent 

 the processes of excitation are than those of depression. Never- 

 theless, these latter possess no less importance for the course 

 of vital phenomena than those of excitation. Without depres- 

 sion no excitation can take place in the vital activity of the organ- 

 ism, for, as we have seen, every excitation is secondarily fol- 

 lowed by a refractory period. To this must be added the great 

 number of primary depressions, directly brought about by the 

 most varied stimuli, such as cold, want of oxygen, poisons, etc., 

 without the presence of a preceding excitation. Thus it is essen- 

 tial that the processes of depression should be studied with no 

 less interest than those of excitation, and it is much to be desired 

 that the former should receive a more detailed analysis than has 

 up to now been the case. Even as it is, extensive material has 



