EXHALATION OF CARBON DIOXIDE. 145 



occurring above the basis-line, and hence a large portion remains unaccounted 

 for by these experiments." 



The comparative observations upon the four persons who were the sub- 

 jects of experiment demonstrated one very important fact ; namely, that the 

 action of different kinds of food upon respiration is modified by idiosyncra- 

 sies and the tastes of different individuals. 



The following are the results of observations upon the effects of different 

 alcoholic beverages taken during the intervals of digestion : 



" Brandy, whiskey, and gin, and particularly the latter, almost always less- 

 ened the respiratory changes recorded, while rum as commonly increased 

 them. Rum-and-milk had a very pronounced and persistent action, and 

 there was no effect on the sensorium. Ale and porter always increased them, 

 while sherry wine lessened the quantity of air inspired, but slightly increased 

 the carbonic acid evolved. 



" The volatile elements of alcohol, gin, rum, sherry, and port- wine, when 

 inhaled, lessened the quantity of carbonic acid exhaled, and usually lessened 

 the quantity of air inhaled. The effect of fine old port- wine was very de- 

 cided and uniform ; and it is known that wines and spirits improve in aroma 

 and become weaker in alcohol by age. The excito-respiratory action of rum 

 is probably not due to its volatile elements." 



From these facts it would seem that the most constant effect of alcohol 

 and of alcoholic liquors, such as wines and spirits, is to diminish the exhala- 

 tion of carbon dioxide. This effect is almost instantaneous, when the articles 

 are taken into the stomach fasting ; and when taken with the meals, the 

 increase in carbon dioxide, which habitually accompanies the process of 

 digestion, is materially lessened. Rum, which was found to be a respiratory 

 excitant, is an exception to this rule. Malt liquors seem to increase the ex- 

 halation of carbon dioxide. " The action of pure alcohol was much more to 

 increase than to lessen the respiratory changes, and sometimes the former 

 effect was well pronounced." 



Influence of Sleep. All who have directed attention to the influence of 

 sleep upon the respiratory products have noted a marked diminution in the 

 exhalation of carbon dioxide. According to Edward Smith, the quantity 

 during the night is to the quantity during the day, in complete repose, as ten 

 to eighteen. 



It has already been stated that there is great diminution in the quantity 

 of oxygen consumed in hibernating animals while in a torpid condition. 

 Regnault and Reiset found that a marmot in hibernation consumed only -fa 

 of the oxygen ordinarily appropriated in the active condition. In the same 

 animal they noted an exhalation of carbon dioxide equal to but little more 

 than half the weight of oxygen absorbed. 



Influence of Muscular Activity. Vierordt, in a number of observations 

 on the human subject, ascertained that moderate exercise increased the average 

 quantity of air respired per minute by nearly nineteen cubic inches (311-4 

 c. c.), and that there was an increase of 1-197 cubic inch (19-63 c. c.) per 

 minute in the absolute quantity of carbon dioxide exhaled. 



