THE CHARACTER AND COMPOSITION OF LYMPH 131 



If a hypotonic solution be mixed with blood, water from the hypotonic solution passes 

 through the cell membrane of the red corpuscles into the stroma, and causes it to swell. 

 The hemoglobin at the same time passes out and goes into solution in the diluted plasma. 

 On the other hand, the addition of a hypertonic solution to the plasma causes the red cor- 

 puscles to lose their water and become crenated. The principles of osmosis have been 

 derived from the action of substances separated by dead animal or plant membranes. It 

 must be, however, remembered that in the application of these principles to processes 

 occurring in the living organism, the cells, forming the various membranes, are an im- 

 portant modifying factor. It is probable that physico-chemical processes, occurring in 

 the protoplasm the cell, may change its permeability to the same substance at different 



THE CHARACTER AND COMPOSITION OF LYMPH. 



The lymph is the fluid which immediately surrounds the tissue cells of 

 the living body. It fills up the spaces between the cells themselves and 

 between the cells and the blood-vessels which ramify among the cell-masses. 

 The lymph, therefore, is an intermediate fluid between blood-plasma on the 

 one hand, and the tissue cells on the other, receiving its ingredients by the 

 passage of fluid from the plasma through the walls of the finer blood-vessels 

 in the one direction, and by the discharge of the substances from the cells 

 themselves in the other. 



The Chemical Composition of the Lymph. Since the chief source 

 of the lymph is the blood-plasma, one would naturally expect that its chemical 

 composition would be very similar to that of plasma, which is in fact the case. 

 The variations that are noted in lymph taken from definite sources no doubt 

 have their origin in the fact that the lymph passes through these organs slowly, 

 and that ingredients peculiar to the necessities of the function and growth 

 of the differentiated tissue of the organ are taken from the lymph in special 

 organs. Lymph obtained from a human lymphatic fistula has been analyzed; 

 the figures from Hammarsten are as follows, though considerable variations 

 appear in the analyses from other authorities: 



ANALYSIS OF LYMPH. 



Per cent 



Water . 94.5 to 96.5 



Solids 3.7 to 5.5 



Albumins 3.4 to 4.1 



Ethereal extract 0.06 to 0.13 



Sugar o.i 



Salts 0.8 to 0.9 



Sodium chloride '. 0.55 to 0.58 



Sodium carbonate 0.24 



Disodic phosphate 0.028 



The most notable fact to be derived from this composition table is the 

 low percentage of proteids present in the lymph. 



The Formation of Lymph. The manner in which the substances 

 in the lymph pass through the walls of the capillaries from the plasma is a 



