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amour iS per day for an adult doing an ordinary day's (muscular) work, 

 supposing neither to gain nor loose weight. 



Albuminoids, 4.2 ozs. ; Fats, 2 ozs.j Carbo-hydrates, 17.6 ozs. 

 Professor W. O. Atwater, of Washington, U.S.A., who has written 

 a splendid series of articles in the " Century" for 1887, on the subject 

 of foods, to which I am largely indebted for material in these lectures, 

 estimates that an average man doing muscular work requires — 



For moderate work, Albuminoids, 4.4 ozs.; Fats, 4.4 ozs.; Carbo- 

 hydrates, 14.4 ozs. 



For hard work, Albuminoids, 5.2 ozs.; Fats, 4.4 ozs.; Carbo- 

 hydrates, 14.4 ozs. 



Professor Parkes says that the food required for a healthy adult is : 

 For laborious occupation, Albuminoids, 6 to 7 oz ; Fats, 3.5 to 4.5 oz ; 

 Carbo-hydrates, 16 to 18 oz; Salts, 1.2 to 1.5 oz. 



At rest, Albuminoids, 2.5 oz; Fat, i oz ; Carbo-hydrates, 12 oz; 

 Salts, .5 oz. 



The harder the work the more nitrogenous (albuminoids) should 

 the diet be. 



The heat of the body in order to be maintained necessitates the com- 

 bustion of a large proportion of the food, probably about ^q of it. This 

 heat, together with the work expended internally in the functions of the 

 heart, respiration, &c., and the external muscular action in locomotion 

 and other voluntary work, represent an amount of energy calculated at 

 about 3,400 foot-tons, t'.f., the force required to raise 3,400 tons i foot 

 high. The heat of the body represents in amount that required to raise 

 48.4 lbs. from the freezing to the boiling point, or in mechanical power 

 would be sufficient to raise 150 lbs. through a vertical height of Sh 

 miles. All this must be provided for by food and oxygen before making 

 any demands on the system for muscular or brain labour. 



Fish as a Brain Food. 



I may here allude very briefly to the common, but erroneous, opinion 

 that brain work requires or is benefitted by a liberal fish diet. This has 

 arisen from statements made to the effect that thought and brain work 

 in general used up a large quantity of phosphorus, and secondly, that 

 fish supplied in abundance this element. Neither of these assertions 

 appears on investigation to be true. The brain tissue consumed by 



