PROPERTIES AND COMPOSITION OF LYMPH 259 



Properties and Composition of Lymph. Lymph taken from the 

 vessels in various parts of the system, or the liquid discharged from the 

 thoracic duct during the intervals of digestion, is either transparent and 

 colorless or of a slightly yellowish or greenish tint. When allowed to 

 stand for a short time, it becomes faintly tinged with red, and frequently 

 it has a pale rose-color when first discharged. Microscopical examina- 

 tion shows that this reddish color is dependent on the presence of a few 

 red blood-corpuscles, which are entangled in the clot as the lymph coagu- 

 lates, thus accounting for the deepening of the color when the liquid 

 has been allowed to stand. 



Lymph has no decided or characteristic odor. It is slightly saline 

 in taste, almost insipid. Its specific gravity is much lower than that of 

 the blood. In the dog it is about 1022. A few minutes after discharge 

 from the vessels, both lymph and chyle undergo coagulation. This 

 process, as regards the chemical changes involved, is identical with the 

 coagulation of the blood, in which the leucocytes play an important 

 part. Lymph collected from the thoracic duct in the large ruminants 

 coagulates at the end of five, ten or twelve minutes, and sets into a mass 

 having exactly the form of the vessel in which it is contained. The clot 

 is tolerably consistent, but there is never any spontaneous separation of 

 serum. 



Although many analyses have been made of lymph from the human 

 subject, the conditions under which it has been obtained render it prob- 

 able that in the majority of instances it was not entirely normal. It will 

 be necessary, therefore, to compare these analyses with observations 

 on the inferior animals ; as in the latter, it has been collected under 

 conditions which leave no doubt as to its normal character. The fol- 

 lowing is an analysis by Lassaigne of specimens of lymph collected by 

 Colin from the thoracic duct of a cow, under the most favorable 

 conditions : 



COMPOSITION OF LYMPH FROM A COW 



Water . , V .' ". ' . . 964.0 



Fibrin . ' . . "' ^ . / .< . . . '.".' 0.9 



Albumin .' : -..-.. 28.0 



Fatty matters. . .' ." ; . . -4 



Sodium chloride . . . -.-.. . '. . 5.0 



Sodium carbonate, sodium phosphate and sodium sulphate . - . I - 2 



Calcium phosphate . . . r - './ -5 



i ooo.o 



The proportions given in the table are by no means invariable, the 

 differences in coagulability indicating differences in the proportion of 

 fibrin-factors, and the degree of lactescence showing variations in the 



