THE INTERNAL ENVIRONMENT 219 



grammes of sugar. His strength and resistance to fatigue are 

 remarkable. Afghans use a substitute for tea called " catha 

 edulis," which enables ^them to make long night marches and 

 increases their muscular strength. ( x ) 



154. Coffee taken as an infusion and isyodynamically to bread, 

 into the ration of two persons who produce 52,147 kilogrammetres 

 of work each, gave an economy of 139 Calories and 246 Calories. 

 Thirty grammes of roasted coffee being taken. ( 2 ) In this role of 

 economy it seems certain that coffee, taken in small quantity, 

 stimulates the muscular and nervous functions,( 3 ) provokes the 

 digestive secretions, and aids the general metabolism. 



155. Cocoa, which contains 16% of theine, as used to make 

 chocolate, acts less energetically than coffee ; but it is more 

 nutritive. 



Kola nuts are richer in cafein by 2 to 3%, and their favourable 

 action on muscular work and intellectual activity is most marked. 



"In the evening/' writes Chevalier, the explorer of the Congo 

 and the Ivory Coast, " when we had to keep awake, not only 

 did we do so easily by chewing a kola nut, but the mental 

 activity was stimulated, and the thoughts flowed from our pens. 

 Our work finished we went to sleep as easily as usual, and we felt 

 no depression the next day." ( 4 ) Fatigue is retarded, and 

 endurance is considerably increased. ( 5 ) 



156. Pimento (capsicum annuum) and butyric acid have also 

 proved to be aliments of economy. Four capsicums introduced 

 into a living ration produced an economy of 298 calories. If the 

 ration is not diminished the weight increases 400 grammes a day 

 on an average, and yet the energetic contribution of these four 

 capsicums only equals 21 Calories. 



Finally, rancid butter, representing 4-21 grms of butyric acid 

 enabled a subject, who produced 48,290 kilogrammetres and 

 expended 3,576-64 Cal. to realise an economy of 485 Calories. 



These few experiments demonstrate the general effect of the 

 nervine aliments on the expenditure. They afford protection 

 to the organic reserves, whose co-efficient of energetic transfor- 

 mation they appear to modify. If condiments salt, vinegar, 

 pepper, etc. are examined in the same way, it is found that they 

 lower the muscular power a little. ( 6 ) 



( l ) J. F. Oven (Journ. of Soc. of Chem. Ind., vol. xxix., p. 1091., 30th 



^t., 1910). 

 ) Jules Amar, loc. cit. 

 v ) F. Ranson (Journal of PhysioL, vol. xlii., p. 144, 1911). 



( 4 ) A. Chevalier and Perrot, Les Kolatiers, p. 471, Paris, 1911. 



( 5 ) W. Barr (Ther. Gazette, vol. xx., p. 221, 1896). 

 () Fere .Travail et Plaisir, 1904, Paris (Alcan), 



