A HARD-WORKING DIET. 357 



differences which are important. Viewed, however, 

 simply as sources of C, H and N, they are nearly 

 of equal value. Three for comparison may suf- 



fice 



C H O N 



Albumen . . . 53 7 15 



Fibrine of muscle 54 7 3. 16 



Casein. . . . 53J 7 



These are given in parts per hundred, omitting very 

 small fractions. 



In this and the next table the amount of oxygen is 

 purposely left out, as the object here is to fix atten- 

 tion on the amounts of C, H and N. It is, however, 

 about 22 per cent, in the nitrogen compounds, 50 in 

 starch and sugar, and 1 1 in the fats. 



As fair types of CARBON COMPOUNDS (which have Carbon 



compounds. 



no N) there may be quoted to be compared with 

 the nitrogenous compounds 



C H O N 



Oils and Fats . . 76 12 g none. 



Starches ... 44 6 ^- none. 



Sugar . . 40 to 42 6 J ? . none. 



Starch is one of those words about which perhaps 

 there is need for a "mutual understanding." It is 

 not used by the chemist exactly in the household or 

 laundry sense, as the " starches " used as food in this 

 country are in wheat, rice, potato, corn flour, sago, 

 arrowroot, &c. 



The range of sugars here given includes cane- 

 sugar, beet-sugar, grape-sugar, &c. 



Looking at the above tables it will be seen that 

 oils and fats contain the largest percentage of carbon. 

 As illustrating how the practical experience of many 



