THE CIRCULATING LIQUIDS OF THE BODY 53 



the capillaries into the lymph-spaces that everywhere occupy 

 the interstices of areolar tissue. But in addition to the 

 constituents of the plasma, lymph appears to contain certain 

 toxic substances produced in the metabolism of the tissues 

 and destroyed in the lymphatic glands. Lymph, as obtained 

 from one of the large lymphatic vessels of the limbs, or from 

 the thoracic duct of a fasting animal, is a colourless or some- 

 times yellowish or slightly reddish liquid of alkaline reaction. 

 Its specific gravity is much less than that of the blood (1015 

 to 1030). It coagulates spontaneously, but the clot is always 

 less firm and less bulky than that of blood. The plasma 

 contains fibrinogen, from which the fibrin of the clot is 

 derived. Serum-albumin and serum-globulin are present in 

 much the same relative proportion as in blood, although in 

 smaller absolute amount. Neutral fats, urea, and sugar are 

 also found in small quantities. The inorganic salts are the 

 same as those of the blood-serum, and exist in about the 

 same amount, sodium preponderating among the bases, as 

 it does in serum. The following table shows the results of 

 analyses of lymph from man and the horse (Munk) : 



Chyle is merely the name given to the lymph coming from 

 the alimentary canal. The fat of the food is absorbed by 

 the lymphatics, and during digestion the chyle is crowded 

 with fine fatty globules, which give it a milky appearance. 

 There may also be in chyle a few red blood-corpuscles, 

 carried into the thoracic duct by a back-flow from the 

 veins into which it opens. Chyle clots like ordinary lymph. 

 The following is the composition of a sample analyzed by 

 Paton, and obtained from a fistula of the thoracic duct in 

 a man : 



* The term ' extractives ' is somewhat loosely applied to organic 

 substances which exist in so small an amount, or have such indefinite 

 chemical characters that they cannot be separately estimated. 



