CHAPTER III. 



EFFECT OF ALCOHOL ON COMPLEX NEURAL ARCS. 



If we increase the complication of the nervous arc, we thereby also 

 increase the sources of normal variability, as well as the difficulties of 

 maintaining the similarity of experimental conditions, while we corre- 

 spondingly decrease the probability of finding a normal invariant by 

 any available statistical method. These difficulties incident to a study 

 of the effect of alcohol on the more complex arcs are doubly unfortunate 

 since the complex arcs represent both the theoretical and the practical 

 climax of the study of the effects of alcohol on the neuro-muscular 

 processes of man. The simpler nervous arcs can be studied in animals. 

 Though the results of animal experiments in this, as in other problems, 

 may not be uncritically transferred to man, yet the bulk of experimental 

 evidence of the effects of alcohol on the lower arcs may be more econom- 

 ically obtained from animals. The effect of alcohol on the more com- 

 plex arcs, however, constitutes a preeminently human problem. 



Increased difficulties do not lessen scientific obligations ; they increase 

 them. They make greater demands on technique, which at any par- 

 ticular stage of technical development operate as limitations of the 

 direction of profitable laboratory experiment. Unfortunately, there is 

 at present scant probability of securing experimental data of scientific 

 reliability with respect to the action of moderate doses of alcohol on the 

 higher mental and moral processes. In our attempt to study system- 

 atically related processes, we have chosen such elementary processes 

 as were likely to throw the most light on the more complex. We must 

 choose such relatively complex processes as are related, on the one 

 hand, to the elementary processes that we have already studied, and 

 on the other hand, to the higher processes that are beyond our experi- 

 mental reach. 



The effect of alcohol on reaction processes has been studied chiefly 

 with respect to the so-called simple, discrimination, and choice reac- 

 tions. These studies began with the experiments of Exner, 1 who found 

 that alcohol increased the duration of reaction time. Dietl and von 

 Vintschgau 2 made a comparative study of the effects of morphine, coffee, 

 and wine, and found that alcohol decreased the reaction time. Krae- 

 pelin 3 experimented with amylnitrite, ether, chloroform, and alcohol 

 and found that moderate doses of alcohol differed from ether and chlo- 

 roform by first decreasing and then increasing the reaction, while 

 Warren, 4 in a paper of fine critical acumen and unexcelled statistical 



! Exner, Archiv f. d. ges. Physiol., 1873, 7, p. 601. 



2 Dietl and von Vintschgau, Archiv f. d. ges. Physiol., 1878, 16, p. 310. 



3 Kraepelin, Phil. Stud., 1883, 1, p. 573. 



4 Warren, Journ. Physiol., 1SS7, 8, p. 311. 



7") 



