212 MANUAL OF PHYSIOLOGY. 



The lymph contains a considerable quantity of carbonic acid 

 gas, about 50 vol. per cent., some of which is readily removed 

 by the air pump, and is, therefore, said to be merely absorbed by 

 the fluid, and some of which can only be removed by the addi- 

 tion of acids, and is therefore considered to be in chemical com- 

 bination. Only mere traces of oxygen have been found in the 

 lymph. 



The quantity of chyle and lymph poured into the blood varies 

 so much that any estimation of the amount entering in a given 

 time is unreliable. 



The following circumstances upon which the variations may 

 depend are instructive : 



1. The ingestion of liquid and solid food causes a great 



increase in the amount of chyle. This is obvious from 

 the change in the state of the lacteal vessels, which 

 from being transparent and almost empty become 

 widely distended and white. 



2. The activity of any organ causes an increase of lymph to 



flow from it. 



3. Impediment to the return of the venous blood from any 



part increases the irrigation, i. e., the lymph. 



4. Increase of the amount or the pressure of the blood flow- 



ing through any part augments the lymph flow. 



5. The administration of curare increases the amount of 



lymph. 



The history of the structural elements or lymph corpuscles, 

 which exist in such numbers in the large lymph channels, re- 

 quires some further discussion, as these cells are composed of 

 active protoplasm, and therefore must be destined for some import- 

 ant function, and are produced by some vital process. 



The origin of the lymph corpuscle is not restricted to any one 

 part of the body or to any special organ. It has been said already 

 that the lymphatic glands are supposed to be the most important 

 source of these cells, because the follicular tissue is filled with 

 them, and the lymph contains a much larger number after it has 

 passed through some lymph glands. In the lymphoid tissue of 

 the spleen they are also very numerous, and no doubt many of 



