THE CIRCULATING LIQUIDS OF THE BODY 49 



100 c.c. of blood. Therefore the total volume of the blood would be 

 600 x 3,000 c.c. And the mass, if the specific gravity was 



1*055, would be 3,000x1*055 = 3,165 grammes. According to this 

 method the blood on the average in man constitutes only 4*9 per 

 cent., or ^.^ of the body-weight (say, 3^ kilogrammes in a 70 kilo 

 man), varying in fourteen persons between ^ and ^. Probably 

 these results are somewhat too small. The amount has recently 

 been estimated at yV of the body- weight (Plesch). But, upon the 

 whole, the method is sufficiently accurate, as shown by control 

 experiments with Welcker's method on animals. In chlorosis and 

 pernicious anaemia the quantity of blood is markedly increased. In 



one case of pernicious anaemia it amounted to of the body- weight. 

 This is due solely to increase in the plasma. 



Fig. 10 (p. 46) illustrates the distribution of the blood in the 

 various organs of a rabbit. The liver and skeletal muscles each 

 contain rather more than one-fourth ; the heart, lungs, and great 

 vessels rather less than one-fourth ; and ~ the rest of the body 

 about one-fifth, of the total blood. Thejddney and spleen of 

 the rabbit each contain one-eighth of their own weight of 

 blood, the liver between one-third and one-fourth of its weight, 

 the muscles only one-twentieth of their weight. 



Lymph and Chyle. 



Lymph has been defined as blood without its red corpuscles 

 (Johannes Miiller) ; it resembles, in fact, a dilute blood-plasma, 

 containing leucocytes, some of which (lymphocytes) are common 

 to lymph and blood, others (coarsely granular basophile cells) 

 are absent from the blood. The reason of this similarity appears 

 when it is recognised that the plasma of tissue-lymph (p. 407) 

 is derived, in large part at any rate, from the plasma of blood 

 by a process of physiological filtration (or secretion) through the 

 walls of the capillaries into the lymph-spaces that everywhere 

 occupy the interstices of areolar tissue, while the lymph of the 

 lymphatic vessels is in turn derived from the tissue fluid. But 

 in addition to the constituents of the plasma, lymph appears to 

 contain certain substances produced in the metabolism of the 

 tissues which pass into it directly. Lymph, as collected from one 

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

 duct of a fasting animal, is a colourless or sometimes 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 



4 



