ACTION OF ALCOHOL UPON CIRCULATION— WOOD AND HOYT. 65 



observations, which were partial truths, the whole truth being' that alcohol does not commonly 

 elevate the blood pressure, but in some cases does so. 



Second. We know of no experiments having been made as to the effect of the exhibition of 

 alcohol upon the blood pressure in dogs suffering - from an infective fever, but the results which 

 we have obtained in dogs are in close concord with those reached by Cabot upon human beings 

 suffering from various infective fevers. 



Third. The only experiments with which we are familiar other than our own upon the action 

 of alcohol on the arterial pressure after section of the spinal cord are those which were made in 

 or about 1900 by Prof. John J. Abel, of Johns Hopkins University. In these experiments the 

 results were exactly like those which we have obtained. In a letter written in 1904 by Professor 

 Abel to Dr. H. C. Wood, Professor Abel states that in all his spinal-cord experiments with 

 alcohol great care was taken to see that the section of the cord was complete, and he further 

 states that except in certain experiments, when owing to the animal having been extremely feeble 

 and having suffered from violent hemorrhage during the operation, the blood pressure was almost 

 exhausted before the administration of the alcohol, alcohol always caused distinct elevation of 

 the arterial pressure after section of the spinal cord. 



Fourth. In regard to the effect of alcohol upon the rate of the blood flow, the only experi- 

 mental record in literature with which we are familiar is that of John C. Hemmeter (N. Y. M. R., 

 xl, 1891), who in a single experiment found that in the dog the blood flow was increased from 

 158 milligrammes per second to 399 milligrammes per second by the exhibition of alcohol. This 

 single experiment is evidently in accord with the results which we have obtained. 



Fifth. In regard to the action of alcohol upon the isolated reptilian heart, much work has 

 been performed by various observers at various times, with results which have been discordant. 

 In our study of the effect of the drug upon the reptilian heart the attempt was made to discover 

 if possible the reason of this discordancy. The method of cutting the Gordian knot adopted by 

 some authorities, namely, the assertion that everybody, who had obtained results different from 

 those which they themselves had reached, did not know how to experiment properly, as already 

 stated, does not seem to us philosophic. Having, however, exhaustively studied this subject 

 already, we now merely state our conviction that the reasons of the discrepancies in literature 

 have been made apparent, and that our results are not exceptional in any way. 



INTERPRETATION. 



The interpretation of the experimental facts which have just been stated does not seem to 

 us difficult. The arterial pressure is the result of the interplay of two antagonistic forces, the 

 propelling power derived from the heart and the frontal resistance offered by the blood vessels. 

 If either of these forces be increased — that is. if the blood vessels be narrowed or the heart power 

 augmented — the arterial pressure will rise. If either of these forces be diminished the arterial 

 pressure will fall. If one of these forces be increased and the other diminished the arterial 

 pressure may rise, may fall, may remain as it has been, according as the balance between the 

 two forces rises, falls, or is maintained. The fact, therefore, that alcohol does not constantly 

 elevate the blood pressure is no proof that it does not stimulate either the heart or the blood 

 vessels, since it is evidently possible that it may stimulate one dominant factor of the blood 

 pressure and depress the other so equally as to maintain the balance. Further, the fact that 

 the influence of alcohol upon the blood pressure is not a constant one suggests the probability that 

 it does disturb one or other dominant blood pressure factor, and is unable always to accurately 

 keep the balance between the two altered forces. 



The second fact in regard to alcohol and the blood pressure is that alcohol notably, consist- 

 ently, and persistently elevates blood pressure after paralysis of the vasomotor system by high- 

 up spinal section. This elevation of the blood pressure can not be due to a local action upon 

 the blood vessel walls, otherwise it would manifest itself before section of the spinal cord, 

 because any local action would necessarily show itself as much before as after removal of the 

 dominant vasomotor nerve control. It appears to us that the effects of alcohol upon the blood 

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