FOOD REQUIRED FOR THE BODY. 151 



derstood, is for the supply of requisite carbon only ; and if the food 

 be less, the carbon will be proportionably diminished. The food must 

 also supply the waste of the muscular part of the body, which in a body 

 full-grown, is daily abstracted by other natural processes. The flesh or 

 muscular parts of animals are colored by blood, but if these be well 

 washed they become white, and are found to be composed of fibrin, a 

 white fibrous substance. The blood consists chiefly of the same sub- 

 stance, and the skin, horn, hair, bones, etc., are composed mostly of 

 gelatin, like glue, and analogous to fibrin, albumen (like the white of 

 an egg,) the curd of milk and the gluten of flour. All these consist of 

 four ultimate principles and in nearly the following proportions : 

 carbon 55, oxygen 20, nitrogen 18, and hydrogen 7, in the 100 parts. 

 Sulphur, phosphorus, etc., are also constituents. The amount of these 

 removed by perspiration, excretions, etc., in 24 hours is about 5 oz., 

 having about 350 grains of nitrogen. These are then to be made up 

 by the gluten of the food. After supplying the carbon of respiration by 

 the If Ibs. of wheat, there is about 3 oz. of gluten left. If 2 oz. of 

 beef be added, containing a proportion of fibrin, there then will be 



Of the 1| Ibs. of bread starch, lg - Gluten, - 3 oz. 



And of 8 oz. of beef, - - - Fibrin, - 2 



5 oz. 



Consumed for respiration and other I Consumed for waste of 

 waste. muscles, &c. 



The 7 Ibs. of potatoes contain about 2 oz. of gluten or albumen ; 

 so that to supply 5 oz. of these substances, beef, eggs, or other animal 

 matter may be eaten. Thus a diet for the preservation of human 

 strength, is easily made up of vegetable and animal food, jointly ; for, 

 to supply this waste and the necessary nitrogen, in the form of gluten, 

 with vegetable food alone, it is obvious that a much larger portion 

 must be consumed. Of wheat-bread alone, 3 Ibs. is necessary to sup- 

 ply the requisite nitrogen, calculating wheat-flour to contain 15 per 

 cent, of gluten. This would leave a superabundance of carbon in the 

 starch, with which the stomach might be burthened if not readily 

 voided. The requisite nutriment may be better supplied, it is thought 

 by If Ibs. of bread, and 4 oz. of cheese. 



To impart the same amount of gluten, 4 Ibs. of rice would be ne- 

 cessary for a man daily. Graminivorous animals are provided with 

 larger stomachs than man, hence vegetable diet is better suited for them, 

 yet a little oil-cake, in which nitrogen abounds, will fatten them more 

 readily than almost any quantity of other vegetable food. The human 

 body, beside the substances we have named, contains much saline mat- 

 ter in the form of sulphates, muriates, phosphates, compounds of pot- 

 ash, magnesia, soda, lime, etc., portions of which daily escape from 

 the body in perspiration, excretion, etc., and all of which are to be 



