THE RELATIONS OF METABOLISM TO FOOD-SUPPLY. 147 
The experiments by Rubner,* which have been already several 
times referred to, include trials in which sugar or starch was fed 
alone. The results are computed as previously described, with the 
additional assumption that all the carbohydrates digested (with the 
exception of small amounts of sugar found in the urine in some 
cases) were completely oxidized in the body. The gain or loss of 
carbon as fat is therefore computed by subtracting from the total 
excretory carbon, first, the carbon due to the protein metabolized, 
and second, that assumed to be derived from the carbohydrates. 
On this basis the results are as follows, the amounts of carbohydrates 
given in the table being those believed to have been actually oxi- 
dized : 
Total Nitrogen | Total Carbon Gain or Loss 
Food. of Excreta, of Excreta,t of Fat, 
Grms. Grms. Grms 
NOth isc ma dn adds Seale eas 1.94 38.18 — 40.99 
76.12 grms. cane-sugar......... 1.45 43.19 — 8.4] 
104.97 “ Ne ee Crasaibaielatens 1.07 47.78 + 0.51 
Nothing esi esac ds wae veer ene 1.86 39.22 — 42.72 
97.3 grms. cane-sugar 1.92 50.69 — 2.95 
17.0 “ ie 1.41 39.52 — 35.80 
143.0 “ ee <a 1.22 46.45 + 23.32 
Nothidde: lisssieasnm diene: 1.32 21.36 | — 21.88 
34 grms. cane-sugar............. 1.41 26.18 — 9.10 
45 “ fe Eo seesblatecbhgg cava Gheds 1.25 29.14 — 7.46 
50“ fe) AS ees asenmiae 1.57 27.68 — 1.64 
Nothing’. jaa:c6snecsea sated seis 1.39 25.79 — 27.86 
Nothing i. 2c: ciraa gees Aoele odie 1.42 26.47 — 28.10 
42.96 grms. starch.............- 1.53 33.28 — 10.54 
INOthing : s..oc-c3 sand eines ed Beal acens 2.00 31.53 — 32.10 
57.38 grms. starch.............- 1.52 ; 39 .67 — 10.74 
Nothing (second day)..........- 2.64 27.86 — 24.97 
94 .36 Ss. cane-sugar 
67.96" starch e ee 1.23 38.94 +116.35{ 
4.70 “ — fat 
In place of the slight increase in the proteid metabolism fre- 
quently noticed when fat is consumed, the tendency of the carbo- 
* Zeit. f. Biol., 19, 357-379; 22, 273. 
+Not including the carbon of the carbohydrates found in feces and urine. 
}Total gain of carbon, computed as fat. Compare, loc. cit., 22, 279. 
