A FEW WORDS ABOUT EATABLES. 679 



During sleep 4*99 grain:;. 



"When lying down and half asleep 5'91 " 



When walking at the rate of two miles an hour 18-10 " 



When walking at the rate of three miles an hour 25-83 " 



When turning the tread-mill at the rate of 28-65 feet in a 



minute -13'97 " 



Similar facts are supplied in numbers by these experimentalists, and 

 also by Fick and Winceslaus, and Traube and Parkes, and Pavy, and 

 other excellent observers in this country and abroad ; but these three, 

 about the correctness of which there can be no doubt, are sufficient to 

 show that the amount of urea in the urine does not supply the measure 

 of this waste of muscular tissue in muscular action, which has to be 

 repaired by lean meat and other nitrogenous food, and that the food 

 you really want to repair this waste may be carbonaceous rather than 

 nitrogenous simple fuel, rather than plastic material. 



C. I shall, I expect, be quite ready for my dinner when I come 

 back. I may have taken more lean meat than I wanted to keep my 

 muscles in trim ; I have not taken more than I seem to want. I have 

 been breakfasting in this way for a long time, and I was never in better 

 trim for a long pull than now. I may be eating too much, but you 

 must allow that I am eating the best kind of food. 



M. I do not say that you are not eating the best kind of food ; I 

 only say that lean meat is not the only kind of nitrogenous food which 

 will serve your purpose. It is impossible to distinguish between the 

 albuminose or peptone into which fibrine is resolved in the process 

 of digestion and the albuminose or peptone into which albumen, or 

 caseine, or gluten, or legumin, is resolved in this process. It is appar- 

 ently of little or no moment whether these various nitrogenous articles 

 of food are derived from the world of animal life or from the world 

 of vegetable life. You must allow that an herbivorous animal is not 

 less vigorous than a carnivorous animal ; and certainly you would find 

 it difficult to show that man, who can live and thrive under the most 

 dissimilar circumstances upon almost any kind of food, is vigorous in 

 proportion to the amount of meat he contrives to consume. 



C. You can hardly wish to depreciate the nutritive value of lean 

 meat. 



31. Certainlv not. All the nitrogenous substances, animal and vesre- 

 table, are resolvable into albuminose in the process of digestion, but 

 not with the same facility in every case. Some of them are digested 

 more easily by some persons than by others ; and, besides, there may 

 be differences in the albuminose itself which are recognizable by 

 chemical means. In your own case, lean meat may be more digestible 

 than any other nitrogenous compound, and the albuminose into which 

 it is converted may be more easily assimilated. In another case, eggs 

 or cheese or macaroni may better suit the requirements of the person 

 taking it. I do not venture to lay down a hard and fast rule for you 



