PLAN OF THE INVESTIGATION. 23 



psychopathic subjects knew whether or not alcohol was being given, 

 they all spontaneously remarked that the dose with alcohol was 

 "stronger" than the other. Even the hard drinker (Subject XIII) 

 specified that it felt warm in the stomach. 



There appear to be only three adequate means for masking the 

 alcohol: capsules, stomach or duodenal tube, and intravenous injec- 

 tions. It seemed to us that the use of any of the three would violate 

 the principle of simplicity; that is, all of them would introduce into 

 the experimental process more or less distracting if not annoying con- 

 ditions which would be subject to enormous adaptive variations as 

 the experiment progressed. Capsules seemed inexpedient because of 

 the size and number that would be necessary to ingest 30 c.c. of 

 alcohol in suitable dilution. Many subjects would apparently be 

 unavailable if large capsules were used, through inability to swallow 

 them. The stomach-tube would doubtless be less objectionable after 

 sufficient practice, but the judgment of various physicians was that it 

 would take some subjects so long to become even relatively indifferent 

 to it that it was inexpedient for us to try it. The use of intravenous 

 injections apparently presented too many possibilities for serious 

 trouble. We believe, however, that if it becomes essential to com- 

 pletely mask the alcohol dose, some one of these devices must be used. 



It seems clear to us that if the alcohol must be masked it must be 

 masked completely, with no unregulated instances of half-knowledge or 

 doubt, controlled only by the subject's impression that the degree of 

 knowledge did not influence the results. The difficulties of really 

 masking the alcohol, the questionable pharmaceutical action of strong 

 flavors, and the final probability that some of the subjects would know 

 what they were getting, or at least be more or less conscious of differ- 

 ences in the doses, led us to scrutinize more closely the grounds for 

 attempting to mask the alcohol and to keep the subject ignorant of the 

 fact that he was taking it. The fundamental theoretical grounds for 

 masking the ingestion of alcohol by the use of control mixtures is the 

 increased similarity of the experimental conditions in normal and in 

 alcohol experiments. Aside from the matter of taste, which should 

 properly be regarded as a part of the total action of the drug, this is a 

 valid ground; but it is significant only if the knowledge that the 

 subject had taken alcohol might probably modify the course of the 

 experiment. In his own case, Rivers 1 was led to suspect just such a 

 modification of the results. He found (p. 20) "that the days on which 

 I took the drug interested me more than the normal days on which 

 nothing was taken." While in his own case the control mixtures w T ere 

 "usually wholly indistinguishable" from those which contained the 

 active substances, Rivers remarks (p. 66), concerning the attempts to 

 disguise the alcohol, that "the disguise is much more difficult than in 



'Rivers, The Influence of Alcohol and Other Drugs on Fatigue, London, 1908. 



