618 METABOLISM, NUTRITION AND DIETETICS 



dextrin, and sugar. But 14 litres of beer would be required to yield 

 15 grammes nitrogen, and 10 litres to give 250 grammes carbon; 

 and nobody, except a German corps student, could consume such 

 quantities. The minimum nitrogen requirement, however, as well 

 as the necessary heat value, could theoretically be covered by 6 or 

 7 litres of good German beer. 



In some cocoas there is as much as 50 per cent, of fat, 4 per cent, 

 of starch, and 13 per cent, of proteins; and in the cheaper cocoas 

 much starch is added. Still, a large quantity of the ordinary 

 infusion would be needed for a satisfying meal. Frederick the 

 Great, indeed, in some of his famous marches dined off a cup of 

 chocolate, and beat combined Europe on it ; but his ordinary menu 

 was much more varied and substantial. 



Alcohol. The great social and hygienic evils connected with the 

 abuse of alcohol, as well as its applications in therapeutics, render 

 it necessary, or at least permissible, to state a little more fully, 

 though only in the form of summary, some of the chief conclusions 

 that may be drawn as to its action and uses. 



(1) In small quantities alcohol is oxidized in the body, a little of it, 

 however, being excreted unchanged in the breath and urine. A certain 

 amount of protein is saved from decomposition when alcohol is taken, 

 just as when fat or sugar is taken. For example, the addition of 

 130 grammes of sugar to the daily food of an individual caused a 

 'sparing' of 0*3 gramme nitrogen. The substitution of 72 grammes 

 alcohol for the sugar caused 0-2 gramme nitrogen to be spared (Atwater 

 and Benedict). Alcohol is therefore to some extent a food substance, 

 although it is not, under ordinary circumstances, taken for the sake of 

 the energy its oxidation can supply, but as a stimulant. 



(2) There is no reason to suppose that this energy cannot be utilized 

 as a source of work in the body. Indeed, a certain amount of alcohol 

 may be normally formed in the tissues as one of the intermediate 

 products in the oxidation of sugar. Heat can certainly be produced 

 from it, but this is far more than counterbalanced by the increase in 

 the heat loss which the dilatation of the cutaneous vessels caused by 

 alcohol brings about. 



(3) It is a valuable drug, when judiciously employed, in certain 

 diseases e.g., pneumonia and puerperal insanity (Clouston). 



(4) Alcohol is occasionally of use in disorders not amounting to 

 serious disease e.g., in some cases of slow and difficult digestion. In 

 these cases it may act by increasing the flow of certain of the digestive 

 secretions, as saliva and gastric juice. This effect seems to more than 

 counterbalance the retarding influence which, except when well diluted, 

 it exerts on the chemical processes of digestion. 



The action of alcohol on the secretion of gastric juice has been studied 

 in a dog with a double gastric and cesophageal fistula. Before or 

 during a sham meal of meat, alcohol diluted with water was given as 

 an enema. After the enema the quantity of hydrochloric acid secreted 

 increased in about the same proportion as the quantity of juice, but the 

 pepsin was diminished, reaching a minimum after three-quarters to 

 one and a quarter hours. The increase in the total quantity of the 

 juice and in the acid over-compensated the moderate diminution in the 

 digestive power, so that the net result was beneficial (Pekelharing). 

 But it must be remembered that strong alcoholic beverages, when mixed 



