SUMMARIES AND CORRELATIONS. 249 



its action. Quite apart from the question of any hypothetical selective 

 effect, alcohol is known to be a source of energy, which some tissues at 

 least seem able to use directly (perfused heart). Under certain con- 

 ditions it is known to act as a local irritant. In large doses at least it is 

 known to be a narcotic belonging pharmacologically to the chloroform 

 group. 



Following the general outline of problems that is indicated by our 

 schema, the action of alcohol is first of all a problem of the resultant of 

 its various possible effects on any given process, as a source of energy, 

 local irritant, and narcotic. For human subjects our data seem to show 

 rather conclusively that in the several neuro-muscular processes which 

 we have investigated, depression overbalances all other effects of 

 alcohol. But we are bound to ask whether the apparent depression is 

 due to a real paralysis of some factor in the direct process, or whether 

 in part or in whole it may not be due to the stimulation of inhibitory 

 mechanisms. In either case we must inquire further whether the effect 

 is peripheral or central; that is, whether the alcohol directly affects 

 the end links in the neural chain, or whether it affects coordination 

 processes in nervous centers. Finally, since the activity of nervous 

 tissue as a whole is modified by the interaction of other tissues, a 

 complete account of the action of alcohol on any given indicator 

 involves the coordinate action of alcohol on all the several processes 

 that may influence the indicator or the central nervous mechanism that 

 operates it. 



This final problem will not be solved until the whole alcohol program 

 is completed. But in the systematic interrelation of the processes 

 which we have measured, as well as in- the variation of the dose, we 

 hoped that our present data would permit some definite contribution to 

 the final solution. With the total problem in mind, our first task is 

 to scrutinize our data for whatever indication they may give with 

 respect to the fundamental interpretative question as to whether or not 

 the apparent depression is due to a stimulation of inhibitory mechan- 

 isms. The second question that we must face is as to whether the 

 alcoholic depression ma}^ not be regarded as conservative or recupera- 

 tive. Thirdly, we shall look for a possible interrelationship of the 

 processes through differences in their temporal incidence, and finally, 

 we shall inquire which of the various effects which we have measured 

 represents the central tendency most completely. This should not 

 only show us something of the general reliability of the measurements 

 for the estimation of personal differences; it should also indicate 

 whether the effects of alcohol are predominantly sensory, motor, or 

 central. 



