i EXCHANGE OF MATEBIAL 37 



grms.) be introduced with the food, a good deal of it (about 

 30 per cent) will be discharged by the kidneys in an unchanged 

 state, and the remainder burnt without causing any great increase 

 in the quantity of carbon dioxide discharged; this suggests that 

 glycerine probably effects a slight saving in the consumption of 

 fat or albumen. 



X. It is important to go briefly into the effect produced on 

 metabolism by the alcoholic drinks which are unfortunately 

 almost always taken apart from meals and by the lower classes 

 both with and between meals. The main ingredient of all 

 fermented drinks, such as wine, beer, brandy, and liqueurs, is 

 alcohol, which is readily absorbed as such, so that it can be 

 distilled from the blood. In the body it is burnt, though not as 

 quickly and entirely as was thought by Liebig. A small portion 

 is exhaled through the lungs, amyl alcohol in larger quantities 

 than ethyl, according to Binz ; another portion is discharged 

 undecomposed in the urine (Sieben) ; the largest portion (98 per 

 cent as a mean according to Atwater) undergoes combustion and 

 is transformed into water and carbon dioxide, developing a 

 certain amount of heat, and therefore serves as combustible 

 material. 



The researches of Zuntz and Berdez (1887), as well as those 

 made at the same time by Geppert, show that alcohol taken in 

 non-toxic quantities does not cause an increase in the quantity 

 of oxygen absorbed or in the amount of carbon dioxide discharged. 

 We must, then, conclude that the combustion of alcohol effects an 

 economy in the consumption of nitrogenous or non-nitrogenous 

 substances. 



The experiments made by Fokker and I. Munk on dogs, when 

 nitrogenous equilibrium had been obtained, showed that alcohol 

 in moderate quantities effected an economy of about 6-7 per cent 

 in the consumption of nitrogen, whereas in quantities, sufficiently 

 large to produce intoxication, it increased this consumption by 

 4-10 per cent. In the former case, according to the researches 

 made by Bock and Brauer, the gaseous respiratory exchange is 

 slightly depressed, while in the latter case it is of course increased. 

 The slight decrease in the discharge of carbon dioxide when the 

 quantities are moderate cannot be due only to economy in the 

 consumption of protein, but must also be due to the sparing of 

 non-nitrogenous substances. The increase in the carbon dioxide 

 when large quantities are taken arises not only from the increased 

 amount of nitrogen consumed, but also from the consumption 

 of fat. 



The more recent experiments upon man made in 1902 by 

 Atwater and Benedict, who determined directly the total exchange 

 of material and the loss of heat, also go to prove that alcohol 

 during combustion can take the place of articles of food not 



