610 EXPERIMENTS DEALING WITH 



transudation, the osmotic pressure of the proteids of the serum 

 determines absorption." 



Lazarus-Barlow explains absorption by the same alternations 

 of osmosis and diffusion, but considers that osmosis has a 

 different origin. According to him, the fluid which contains a 

 greater concentration of proteid will always in the end increase 

 in quantity at the expense of a fluid which contains a less con- 

 centration, because of the different degrees to which the membrane 

 is clogged on its two sides by proteid. The concentration of 

 diffusible substances is in consequence slightly greater on the side 

 with more proteid, and osmosis is started. 



Starling has applied the same factors the osmotic pressure of 

 proteids and the relative impermeability of the capillary wall to 

 the explanation of the accurate regulation of the volume of the 

 circulating blood. He points out that, granted his premises, there 

 will always exist a relation between the capillary pressure and the 

 osmotic attraction of the blood proteids for extra vascular fluid. 

 This relation must be one of balance, unless one force is stronger 

 than the other, when either transudation or absorption will take 

 place, as the case may be. If by any means the capillary 

 pressure is increased, more fluid containing a less concentration 

 of proteid will be transuded. This will go on until the increased 

 filtering force is balanced again by an increased absorbing force, 

 represented by the now greater difference in the proteid concen- 

 tration on the two sides of the capillary wall. And when a fresh 

 point of balance has thus been reached, the tissue spaces will be 

 filled with a larger quantity of fluid derived from the blood. 

 With a fall in capillary pressure exactly the opposite will happen. 

 The decreased filtering force will become balanced by a diminution 

 in the absorbing force. This will take place by isotonic fluid being 

 absorbed into the capillaries, thus raising the proteid concentration 

 in the extravascular fluid and reducing the difference in proteid 

 concentration on the two sides of the capillary wall. When the 

 decreased absorbing force again balances the decreased capillary 

 pressure, the tissue spaces will contain less fluid than before and 

 the blood more. 



Starling has observed that lymph in the lymphatics from 

 different parts of the body contains very different percentages of 

 proteid. Lymph from a limb has 2 to 3 per cent., that from 

 the intestines 4 to 6 per cent., and that from the liver 6 to 8 



