62 GRAHAM LUSK 



A very small quantity of carbon, hydrogen and oxygen (3 to 5 per 

 cent) and a lesser portion of the sulphur as sulphid of iron were elimi- 

 nated in the feces, but the greater portion of the sulphur was eliminated 

 in the urine in the form of sulphuric acid. 



From the data available they calculate the oxygen necessary for the 

 oxidation of the materials metabolized by the- dog. They note that 

 Regnault and Reiset obtained a relatively greater volume of oxygen ab- 

 sorbed than volume of carbon dioxid given off and attribute this to the 

 fasting condition of the animals, since fat contains relatively more hydro- 

 gen than protein and therefore more water was produced at the expense 

 of oxygen absorbed than in the case of a protein diet. Bidder and Schmidt 

 estimate the respiratory quotient of a meat-fed dog to be 0.84. 



They further estimate that five per cent of the total carbonic acid ex- 

 pired passes through a stage of intermediary metabolism by way of the 

 bile. 



In a fasting cat Bidder and Schmidt determined daily for eighteen 

 days the water eliminated in the urine and feces, the urea, sulphuric and 

 phosphoric acids in the urine, the expired carbonic acid and (for ten 

 days) the dried solids of the bile. From the nitrogen excreted they cal- 

 culated the quantity of carbon attributable to the protein metabolism of 

 the time. Subtracting this protein carbon elimination from the total 

 carbon elimination in the urine, feces and respiration, they were able to 

 calculate the quota of respiratory carbon attributable to fat metabolism 

 and from this the quantity of fat metabolized during the fasting period. 

 This is again the method followed by Pettenkofer and Voit. 



They make the following table to represent the starvation period 

 (eighteen days) : 



From the metabolism of C H. N O S P 2 O 5 



204.43 gm. protein ... 102.24 13.43 30.81 43.81 

 132.75 gm. fat 103.72 15.59 13.45 



Total 205.96 29.02 30.81 57.26 2.167 3.761 



Excreted by lungs, urine 



and feces . . 205.96 4.67 30.81 18.42 1.127 3.565 



Rest (to be expired as 



water) 24.35 38.84 



O 2 Gm. 



190.78 gm. expired C require to produce CO 2 ... 508.74 

 24.347 gm. " H " " " " H 2 O . . 194.78 



703.52 

 Less O 2 contained in the products of metabolism. . . . 38.84 



Oxygen which must have been used 664.68 



