320 IMBIBITION AND EXHALATION. 



the chyle is also richer than the lymph in albuminous matters, the 

 principal difference between them consists in the proportion of fat. 

 This is shown by the following comparative analysis of the lymph 

 and chyle of the ass, by Dr. Bees:' 



1,000.00 1,000.00 



When a canula, accordingly, is introduced into the thoracic duct 

 at various periods after feeding, the fluid which is discharged varies 

 considerably, both in appearance and quantity. We have found 

 that, in the dog, the fluid of the thoracic duct never becomes quite 

 transparent, but retains a very marked opaline tinge even so late 

 as eighteen hours after feeding, and at least three days and a half 

 after the introduction of fat food. Soon after feeding, however, as 

 we have already seen, it becomes whitish and opaque, and remains 

 so while digestion and absorption are in progress. It also becomes 

 more abundant soon after the commencement of digestion, but 

 diminishes again in quantity during its latter stages. We have 

 found the lymph and chyle to be discharged from the thoracic duct, 

 in the dog, in the following quantities per hour, at different periods 

 of digestion. The quantities are calculated in proportion to the 

 entire weight of the animal. 



PER THOUSAND PARTS. 

 3 hours after feeding . . . , . .2.45 



7 2.20 



13 0.99 



18 " " " 1.15 



18} "" " 1.99 



It would thus appear that the hourly quantity of lymph, after 

 diminishing during the latter stages of digestion, increases again 

 somewhat, about the eighteenth hour, though it is still considera- 

 bly less abundant than while digestion was in active progress. 



The lymph obtained from the thoracic duct at all periods coagu- 

 lates soon after its withdrawal, owing to the fibrin which it contains 



1 In Colin, op. cit., vol. ii. p. 18. 



