428 POPULAR SCIENCE MONTHLY 



it into fatty acid and glycerine. This action, according to ferment law, 

 would continue till a mixture of fat and fatty acid in chemical equilib- 

 rium was produced. But in the intestine, absorption begins and 

 fatty acid is removed as fast as formed, thus allowing the ferment to 

 continue its action as long as any fat remains in the intestine. But if 

 both fatty acid and ferment are absorbed together, then, as soon as they 

 get inside the absorbing cell, the ferment in the presence of fatty acid 

 only will begin its work over again, which then will be the formation 

 of droplets of neutral fat from the fatty acid absorbed. 



This view rests on the assumption that fat ferment accompanies 

 the fat from intestine to tissue. The observers mentioned have in- 

 vestigated this subject. They examined a large number of fat-contain- 

 ing tissues and organs, and found in every case that they contained fat 

 ferment about in the proportion that they contained fat, except that the 

 liver contained a very active ferment out of proportion to the amount of 

 fat in that organ. 



The fat absorbed from the intestine finds its way into the lymphatics 

 and thence to the thoracic duct, there to be mingled with the blood. 

 Shortly after a meal if the blood serum of an animal be taken and 

 allowed to stand a layer of fat forms on top. The serum taken some 

 hours after a meal, on standing forms no such layer, showing that fat 

 rapidly disappears from the blood. And here arises one of the in- 

 teresting problems of fat metabolism. What becomes of fat when it 

 disappears from the blood and what is the origin of the fat in the 

 tissues ? A very simple explanation would be that the fat of the blood 

 is deposited in the tissue cells. Another theory, and one that has had 

 the sanction of good authority, is that the fat in the tissues is made 

 there from their own proteid substance. 



In favor of the transformation of proteid into fat are usually men- 

 tioned the following: In the ripening of cheese, fat is increased at the 

 expense of proteid. In certain damp soils corpses have their proteid 

 converted into a fatty substance known as adipocere. Both of these 

 arguments are somewhat less convincing when it is known that bacteria 

 are the active agents of these changes. As the result of various poisons 

 — notably phosphorus — the liver is found to contain large quantities 

 of fat in the form of droplets in the injured cells of the organ. This 

 has been called fatty degeneration and the protoplasm of the de- 

 generating cells in one stage of degeneration was thought to be changed 

 to fat. On the other hand, it is claimed that if an animal is first 

 starved, so that fat disappears from the body, and then poisoned 

 with phosphorous, no fat appears in the liver. There is too other 

 evidence of an experimental nature to show that the fat of fatty de- 

 generation is fat transported from the usual depots of fat and simply 



