270 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



comes to the definite conclusion that alcohol has a twofold influence upon the metabolism of pro- 

 tein, as previously suggested by Neumann. He is inclined to believe, with Neumann, that the 

 disintegrating action is most apt to occur with persons little accustomed to the use of alcohol, and 

 is of short duration, while in its action as a protector of protein it is analogous to the carbohy- 

 drates and fats, its influence being due to the utilization of its energy by the body. According to 

 this view, the results obtained by Miura and others, in whose experiments the alcohol periods 

 continued only from four to six days, are explained by the disintegrating action of the alcohol, 

 which counteracted the protecting action, so that the resultant effect was an apparent failure of 

 the alcohol to protect protein. With Neumann the alcohol periods continued after this disin- 

 tegrating action ceased, and showed the more permanent protecting influence. The fact that in a 

 number of the experiments the protecting influence was manifested from the start is explained 

 by the absence or only partial action of the disintegrating tendency. 



We have, then, a clearly defined theory regarding the influence of alcohol upon proteid 

 metabolism. This theory assumes two different kinds of action of alcohol. In the one it is a direct 

 protector of protein, and serves the body as food; in the other it tends to disintegrate protein, 

 and acts as a drug. The belief in the first action follows as a corollary from the oxidation of 

 alcohol in the body and the transformation of its energy. In undergoing these changes alcohol 

 is similar to sugar, starch, and fat, which, by their own oxidation and consequent supply of 

 energy to the body are able to protect the constituents of the food and of the body, including 

 protein, from oxidation. That alcohol may and does protect protein is abundantly demonstrated 

 by the experiments above cited. 



The disintegrating influence of alcohol upon protein is less definitely proven. The theory 

 is little more than a convenient hypothesis for explaining the failure of alcohol, under some 

 circumstances, to protect protein. It is the only satisfactory hypothesis which has thus far 

 been suggested. It is all the easier to accept because of the considerations that the breaking 

 up of protein compounds in the body seems to be influenced, in some unexplained way or ways, 

 by the nervous system, and this latter in turn is influenced byalcohol. In our own experiments, 

 for instance, the excretion of nitrogen is apparently affected at times by the mental condition of 

 the subject. 



In large enough doses alcohol has a paralyzing effect, and may thus reduce general metabolism 

 to a minimum and cause coma or even death. There is no proof that it can not, on the other 

 hand, increase proteid metabolism. 



The positive proof of the disintegrating action of alcohol upon protein is limited in amount. 

 The experimental demonstration must be sought in cases in which more protein is broken down 

 with alcohol than without it, the ration of ordinary food being otherwise the same in both 

 cases. We have been able to find only three cases on record in which the amount of protein 

 thus broken down with alcohol apparently exceeded by more than 0.1 gram of nitrogen per dav 

 the amount broken down without alcohol. They are discussed in the review above referred to. 

 The first was in one of Miura's experiments, in which the excess with alcohol amounted to 

 0.5 gram of nitrogen (3.2 grams of protein) per day during an alcohol period of four days. 

 The second was in one of Neumann's experiments, in which the excess during the first four 

 days of an alcohol period of ten days was 0.9 gram of nitrogen per da}'. During the remaining 

 six days of the same period the nitrogen excretion was less by 1.5 grams per day than in the 

 corresponding period without alcohol. The third was in an experiment by Clopatt. During 

 the first six days of an alcohol period of twelve days the nitrogen excretion exceeded that of 

 a corresponding period without alcohol by 2 grams per day. During the remaining six days 

 of the same alcohol period the nitrogen excretion was less by 1.4 grams per day than it was 

 without alcohol. 



Il seems to the writers that in view of the unavoidable irregularities in the nitrogen balance in 

 such experimenting these data are insufficient to demonstrate the disintegrating action of alcohol, 

 Imt. taken in connection with the need of an explanation for the occasional failure of alcohol to 

 protect protein, they make the theory plausible. 



