THE USE AND ABUSE OF FOOD. 337 



for nitrogenous food. In the same manner the amount of 

 urea is the representative of the amount of muscular work 

 done." 



It has been calculated that the average amount of urea 

 daily formed in the body of a healthy man is about 470 

 grains. To supply this daily consumption of nitrogenous 

 matter, it is necessary that about four ounces of flesh-forming 

 substance should be consumed daily. It is important, 

 therefore, to inquire how this substance may be obtained. 

 The requisite quantity of albuminous and fibrinous matter 

 "is contained," says Dr. Lankester, " in a pound of beef ; in 

 two pounds of eggs ; in two quarts of milk ; in a pound of 

 peas ; in five pounds of rice ; in sixteen pounds of potatoes ; 

 in two pounds of Indian meal ; in a pound and a half of 

 oatmeal ; and in a pound and three-quarters of flour." A 

 consideration of this list will show the importance of attend- 

 ing to the quality as well as the quantity of our food. A 

 man of ordinary appetite might satisfy his hunger on potatoes 

 or on rice, without by any means supplying his system with 

 a sufficient amount of flesh-forming food. On the other 

 hand, if a man were to live on bread and beef alone, he 

 would load his system with an amount of nitrogenous food, 

 although not taking what could be considered an excessive 

 amount of daily nourishment. We see, also, how it is 

 possible to continually vary the form in which we take the 

 required supply of nitrogenous food, without varying the 

 amount of that supply from day to day. 



The supply itself should of course also vary from day to 

 day as the amount of daily work may vary. What would be 

 ample for a person performing a moderate amount of work 

 would be insufficient for one who underwent daily great 

 bodily or mental exertions, and would be too much for one 

 who was taking holiday. It would appear, from the re- 

 searches of Dr. Haughton, that the amount of urea daily 

 formed in the body of a healthy man of average weight varies 

 from 400 to 630 grams. Of this weight it appears that 300 

 grains results from the action of the internal organs. It 



