1048 



EXPERIMENT STATION RECORD. 



oxidi/.od 41). 2 grams of the protcid tissues of his l)ody in Jiddition to 

 14().8 oranis of proteids and 16.3 granis of nonproteids which he was 

 shown to liavc di<,n\sted from Ills feed. In I\'riod B the k)ss of pro- 

 teids was only 7.2 grams on a ration containing in digestible form 

 178.2 grams of proteids and 17.2 grams of nonproteids. In other 

 Avords, the second ration diminished the k)ss of proteids by the l)ody 

 by 42.0 grams, while it supplied only 26.4 grams more of prot(Mds than 

 that of Period A. This striking result is readily explained as the 

 efi'ect of the large addition of nonnitrogenous matter in Period B, l)ut 

 it serves to illustrate the difficulty of drawing a prior! conclusions as 

 to the effects of a ration. 



The animal body, however, usually contains relatively considerable 

 amounts of fat, and the quantity of the latter is subject to nuich 

 greater fluctuations than that of protein. The change in the store of 

 fat in the body is usually the most conspicuous efl:ect of a ration. The 

 determination of its amount requires, in addition to the nitrogen 

 balance, a determination of the income and outgo of carbon, including, 

 therefore, a determination of the gaseous products of respiration and 

 perspiration by means of some form of respiration apparatus. 



In the two periods whose nitrogen balance has just been given, the 

 respiratory products were also determined for 48 hours by means of 

 the respiration calorimeter, afl'ording, along witli determinations of 

 carbon in feed and excreta, data for the following daily comparisons: 



Income and outgo of cnrhon. 



Carbon of hay 



Carbon of linseed meal . . . 



Carhon of feces 



Carbon of urine , 



Carbon of carbon-dioxirt . 



Carbon of methane 



Carbon of hair, etc 



Carbon lost by body 



Total. 



Period A. 



Income. Outgo, 



Grams. 



1, 337. 6 



172. 5 



1,735.2 



Grams. 



649.8 

 88.1 



934.1 

 55.2 

 8.0 



1, 735. 2 



Period B. 



Income. Outgo, 



Grams. 



1,876.8 



170.7 



65.8 



2,113.3 



Grams. 



85S.0 



101.3 



1 , 075. 6 



70.4 



8.0 



2,113.3 



In Period A we have already computed a daily loss of 49.2 grams of 

 protein. This protein contains .52.54 per cent of carbon, equal to 25.9 

 grams, while the total loss of carbon, as shown above, was 225.1 

 grams. The difl'erence of 199.2 grams must, therefore, according to 

 our basal assumption regarding the make-up of the schematic bod}^ 

 represent a loss of fat, and since this fat contains 76.5 per cent of 

 carbon, the loss of 199.2 grams is equivalent to the loss of 259.0 grams 

 of fat. In precisel}^ the same way, w^e compute the loss of fat in 

 Period B to be 80.6 grams. 



