FOODS AND DIETARIES 



241 



Note. Should one desire to add further items to the above table, ob- 

 tain Bulletin 28, U. 6. Department of Agriculture, " The Chemical Com- 

 position of American Food Materials," by Atwater and Bryant. (Send 

 5 cents in coin to Superintendent of Documents, Washington, D.C.) The 

 weight in ounces of a standard portion equals 1600 divided by number of 

 calories per pound given in table. The calories furnished by proteid equal 

 the percentage of proteid given in the Bulletin table multiplied by 1860 

 and divided by the number of calories per pound. The same calculation 

 and factor applies to carbohydrates. For fat, calculate the same way, 

 but use the factor 4220 in place of 1860. Verify the three results by add- 

 ing to see if they equal 100 calories. 



d. Food Values (Method II, Graphic) 



Observations. 1. The threefold constitution of any partic- 

 ular food may be represented graphically by the position 

 of a point in a triangle CPF (Fig. 56). Thus the pcint 

 O, representing milk, is 

 located at a height above 

 CF, 19% of the total 

 height of P } which shows 

 that 19% of the food 

 value of milk is proteid ; 

 and at a distance to the 

 right of CP towards F, 

 52% of the distance, 

 signifying that 52 % of 

 the food value of milk is 

 fat. Where would you 

 locate the point for a 



*0 JO 



70 80 90 100 



Fia. 56. Food map. Composition of 

 milk represented by the point 0. 

 (After Fisher.) 



food which was 90% 

 proteid? 90% fat? 



Conclusions. 1. Ex- 

 plain how P might be 



called the proteid corner, F the fat corner, and O the carbohy- 

 drate corner. 



2. On what line would a food devoid of proteid be located ? 

 If devoid of fat ? 



SHARPE'S LAB. MAN. 16 



