126 RESPIRATION 



lessened the respiratory changes recorded, while rum as commonly in- 

 creased 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 decided 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 exhalation 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 accom- 

 panies the process of digestion, is materially lessened. Rum, which 

 was found to be a respiratory excitant, is an exception. Malt liquors 

 seem to increase the exhalation 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 on 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. Regnault and Reiset found that a marmot in hibernation 

 consumed only one-thirtieth 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. The results of the experiments of 

 Dr. Edward Smith on the influence of exercise are as follows : 



In walking at the rate of two miles (3.22 kilometers) per hour, the 

 exhalation of carbon dioxide during one hour was equal to the quantity 

 produced during i| hour of repose with food or 2\ hours of repose 

 without food. 



Walking at the rate of three miles (4.828 kilometers) per hour, one 

 hour was equal to 2-f hours with food or 3^ hours without food. 



One hour's labor at the tread-wheel, while actually working the 

 wheel, was equal to 4^ hours of rest with food or 6 hours without food. 



