676 ABSORPTION. 



the foot of a female ; and M. Magendie one around the corona glandis 

 of a male. In dogs, cats, and other living animals, lymphatics, filled 

 with lymph, are frequently seen at the surface of the liver, gall-bladder, 

 vena cava, vena portae, and at the sides of the spine. Magendie re- 

 marks, that he has never met with the thoracic duct empty, even when 

 the lymphatics of the rest of the body were entirely so. 1 It must be 

 recollected, however, that the thoracic duct must always contain the 

 product of the digestion either of food or of secretions from the aliment- 

 ary tube. The stagnation of lymph in particular vessels has given 

 occasion to the belief, that it flows with different degrees of velocity in 

 different parts of the system; and this notion has entered into the 

 pathological views of writers, who have presumed, that something like 

 determinations of lymph may occur, and produce lymphatic swellings. 

 M. Bordeu, 2 indeed, speaks of currents of lymph. All the phenomena 

 of the course of the lymph negative, however, this presumption ; and in- 

 duce us to believe, that its progress is pretty uniform, and always slow; 

 and when an accumulation, or engorgement, or stagnation occurs in 

 any vessel, it is more probably owing to increased formation by the 

 lymphatic radicles that communicate with the vessel in question, or to 

 loss of tone in the parietes of the engorged lymphatics. 



The lymph, which proceeds by the thoracic duct, is emptied, along 

 with the chyle, into the subclavian vein. At the confluence, a valve 

 is placed, which does not, however, appear to be essential, as the duct 

 opens so favourably between the two currents from the jugular and 

 subclavian, that there is little or no tendency in the blood to reflow into 

 it. It has been suggested, that its use may be, to moderate the instilla- 

 tion of the fluid from the thoracic duct into the venous blood. 



With regard to the question, whether the lymph is the same at the 

 radicles of the lymphatics as in the thoracic duct, or whether it does 

 not gradually become more and more animalized in its course towards 

 the venous system, and especially in its progress through the lymphatic 

 glands, the remarks made upon this subject, as respects the chyle, apply 

 with equal force to the lymph. Our ignorance is no less profound. 



The glands of the mesentery, and lymphatics in general, seem to be 

 concerned in some of- the most serious diseases. Swelling of the 

 lymphatic glands of the groin may indicate the existence of a venereal 

 sore on the penis. A wound on the foot produces tumefaction of the 

 inguinal glands ; one on the hand inflames those of the axilla. When- 

 ever, indeed, a lymphatic gland is symptomatically enlarged, the source 

 of irritation will be found at a greater distance from the vein into wh&h 

 the great lymphatic trunks pour their fluid than the gland is. In 

 plague, one of the essential phenomena is swelling of the lymphatic 

 glands of the groin and axilla; hence, it has been termed adeno-ady- 

 namic fever (from aS^, a gland). In scrofula, the lymphatic system is 

 generally deranged; and, in the doctrine of Broussais, a very active 

 sympathy is affirmed to exist between the glands of the mesentery, and 

 the mucous surface of the stomach and intestines. This discovery, we 

 are told, belongs to the "physiological doctrine" which has shown, that 



1 Precis, &c., ii. 224. 2 (Euvres completes, par Richerand, Paris, 1818. 



