372 THE LYMPHATIC SYSTEM. 



sized cow, the smallest quantity obtained, in an experiment extending 

 over a period of twelve hours, was 625 grammes in fifteen minutes ; that 

 is, 2500 grammes per hour, or 60 kilogrammes per day. In another 

 experiment with a young bull weighing 185 kilogrammes, he actually 

 withdrew from the thoracic duct in the course of twenty-four hours, 15 

 kilogrammes of lymph and chyle, representing a little more than 8 per 

 cent, of the entire bodily weight of the animal. 



We have obtained similar results from experiments upon the dog and 

 goat. In a young kid weighing 6.36 kilogrammes, we have obtained 

 from the thoracic duct 122.5 grammes of lymph in three hours and a 

 half. This quantity represents 35 grammes per hour, and, if continued 

 throughout the day, would amount to 640 grammes, or fully 10 per 

 cent, of the entire bodily weight. In the dog the fluids discharged from 

 the thoracic duct are less abundant. The average of all the results 

 obtained by us, in this animal, at different periods after feeding, gives 

 very nearly four and a half per cent, of the bodily weight, as the total 

 daily quantity of lymph and chyle. This is substantially the same 

 result as that obtained by Colin in the horse ; and for a man weigh- 

 ing 65 kilogrammes, it would be equivalent to about 3000 grammes 

 of lymph and chyle per day. But this quantity represents both the 

 products of tymphatic transudation and those of intestinal absorption 

 taken together. An estimate of the total amount of the lymph alone 

 must be based upon the quantity of fluids passing through the thoracic 

 duct in the intervals of digestion, when no chyle is being taken up from 

 the alimentary canal. In the dog, as shown by the experiments quoted 

 above, the average quantity obtained, from the thirteenth to the eigh- 

 teenth or nineteenth hour after feeding, when intestinal absorption had 

 come to an end, was about 1.30 per thousand parts of the bodily weight ; 

 or, for the whole twenty-four hours, a little over 3 per cent, of the bodily 

 weight. For a man of medium size, this would give not far from 2000 

 grammes as the average daily quantity of lymph alone. 



Internal Renovation of the Animal Fluids. By the combined actions 

 of secretion, transudation, and reabsorption, a continual interchange or 

 renovation of the animal fluids takes place in the living body, which is 

 dependent for its materials upon the circulation of the blood, and which 

 may be considered as a kind of secondary circulation through the sub- 

 stance of the tissues. For all the digestive fluids, as well as the bile 

 discharged into the intestine, are reabsorbed in the natural process of 

 digestion and again enter the current of the circulation. These fluids, 

 therefore, pass and repass through the mucous membrane of the alimen- 

 tary canal and adjacent glands, becoming more or less altered in con- 

 stitution at each passage, but still serving to renovate alternately the 

 constitution of the blood and the ingredients of the digestive secretions. 

 The elements of the blood itself also transude in part from the capillary 

 vessels, and are again taken up from the tissues by the lymphatics, 

 to be finally restored to the venous blood, in the immediate neighbor- 

 hood of the heart. 



