60 GRAHAM LUSK 



Neutral fat in a melted state penetrates the epithelia of the intestinal 

 wall provided the same is covered with bile in a living animal, whereas 

 it is impermeable to fat when it is not covered with bile. There is a 

 greater attraction for fat in the former case. If two capillary tubes be 

 taken and one be soaked in fresh bile, the other in water or normal 

 saline, and then both be dipped in oil, the fat will rise much higher in 

 the tube dipped in bile than in the other tube (we moderns would call 

 this a diminution of the surface tension). 



They state that when the bile is drawn off through a biliary fistula 

 there is an increased intake of other food to compensate for the losses 

 through the bile. 



Is the absorbed bile eliminated through the kidneys or through the 

 lungs ? The nitrogen content is too small to contribute much to the 

 nitrogen content of the urine, and hence Liebig concluded that bile was 

 a respiratory material (material fit for respiration), yielding carbon 

 dioxid and water as end products. Certainly, all the carbon of the respi- 

 ration does not have to pass through the bile prior to oxidation, for the 

 total bile contains only 0.5 gm. of carbon, the expired air 8.6 gm. of 

 carbon per kilogram of body weight in the dog in twenty-four hours. 

 However, the 0.035 gm. of nitrogen eliminated in the bile per kilogram of 

 body weight might readily be that quantity which was liberated as free 

 nitrogen and was expired in the respiration. 



Bidder and Schmidt describe what is now known as "basal metabol- 

 ism," as follows : "For every species of animal there is a typical minimum 

 of necessary metabolism which is apparent in experiments when no food 

 is given (im niichternen Zustande). The excess over and above this 

 necessary measure of typical metabolism can be termed luxury con- 

 sumption, although the well-being and the energy of all the functions of 

 life are considerably increased through this increased activity of 

 metabolism." 



Bidder and Schmidt now attempt the first computation of the total 

 metabolism, as calculated from the respiratory as well as from the urinary 

 and fecal pathways of elimination. They say, "To give the total figures 

 would involve too much printing." The following was an experiment of 

 June, 1847, accomplished on a pregnant dog. 



In the first place they give the following elementary analysis of dry 

 meat free from ash : , : 



C 53.01 per cent 

 H 7.02 

 N 16.11 

 O 22.86 

 S 1.00 



100.00 



