66 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. N, NO. 3. 



pressure before and after section of the cervical cord are when taken together in themselves 

 sufficient to show that alcohol concentaneously stimulates the heart and depresses the vasomotor 

 centers. This conclusion is very strongly corroborated by the effect of alcohol in increasing the 

 rate of the blood flow in the arteries. The blood flow may be increased by augmenting the force 

 of the propelling power, or by diminishing the power of the resistance, or it may be enormously 

 increased by simultaneously increasing the propelling power and decreasing the resistance. We 

 have demonstrated that the rate of the blood flow is almost doubled by alcohol; indeed the 

 amount of this increase is so great as in itself to suggest that there must be a double factor in its 

 production. That the increased rate of blood flow is not caused by or consistently accompanied 

 with increase in the arterial pressure we have demonstrated. Either simply cardiac stimulation 

 or simple vasomotor constriction would increase the arterial pressure. Moreover, if an increase 

 of the blood flow produced by the drug were simply due to cardiac stimulation, such cardiac 

 stimulation would of necessity clearly register itself in the uninjured animal by a rise of the 

 blood pressure, and this alcohol does not do; further, if the increased blood flow were the out- 

 come of vascular depression, of necessity alcohol should in the uninjured animal produce fall of 

 the blood pressure. 



These three facts taken together, namely, lack of power to consistently increase or decrease 

 blood pressure in the uninjured animal; possession of power to increase blood pressure after 

 centric vasomotor paralysis; possession of power to enormously augment the rate of the blood 

 flow, lead to one inevitable conclusion, namely, that a drug which possesses these things must 

 simultaneously stimulate the heart and widen the blood paths by depressing the vasomotor 

 centers. Such, then, must be the action of alcohol. 



The correctness of this conclusion is further corroborated by the results of our study of the 

 action of alcohol upon the isolated reptilian heart. It would, apparently, have been in order to 

 have made studies upon the mammalian heart, but we have long since believed, as the result of 

 careful study of the experimental methods and results heretofore published, that such experi- 

 mentation is so surrounded with practical difficulties that the results reached are more apt to be 

 misleading than true guides. The delicacy of the organ, the violence done to its natural condi- 

 tions, the unexplainable results which have been reached by various experimenters seem to us to 

 show that until the technique of the method is radically improved little can really be learned 

 from such experiments unless in the case of a drug like digitalis, whose cardiac action is 

 overwhelming. 



On the other hand, the power of the reptilian heart under favorable circumstances to con- 

 tinue at ordinary temperatures its functions for many hours regularly and without pronounced 

 abatement evinces a lack of sensibility and a robustness of resistance to unnatural conditions 

 which are the basis of successful experimentation. Moreover, all our physiological and pharma- 

 cological data show that, so far as quality of drug action is concerned, there is no difference 

 between the mammalian and reptilian heart. We can. therefore, confidently add to the facts 

 previously summarized the further fact that there is direct proof that alcohol increases the heart 

 work. 



CONCLUSION. 



Alcohol does not seriously affect in tin normal animal blood pressure; elevates the Hood pres- 

 sure after vasomotor paralysis from net inn of the cervical cord; increases enormously the rate of 

 the Hood flaw; directly stimulates th, heart; therefore the general action upon the circulation 

 of the moderate dose of alcohol is great increase in tin rapidity of the circulation caused by 

 cardiac xti /nidation, with eascular (Hiatal inn due to depression of the vasomotor centers. 



Hainan experiments. — The conclusion just reached rests, as does most of our knowledge, in 

 regard to the physiological action of drugs, upon experiments made upon the lower animals; 

 but it has occurred to us that these results might with a certain measure of plausibility be tested 

 by plethysmographic studies upon human beings. Some experience with the plethysinograph 

 has led us to believe that with this instrument incorrect results can very readily be reached, and 

 that too much reliance can readily be placed upon its indications. When the arm is used as 



