264 APPLIED PHYSIOLOGY 



from the intestine has already been described (pp. 30 and 

 37) ; the fat, after being reconstituted in the cells covering 

 the intestinal villi, enters the lacteals, and thence passes 

 to the thoracic duct, forming with the lymph the milky 

 fluid termed 'chyle.' The composition of the chyle 

 discharged from wounds of the thoracic duct in man 

 varies considerably with the amount of fat in the diet, 

 but as a rule it contains about 92'5 per cent, of water, 

 3 to 4 per cent, of protein, 0*5 per cent, of salts, and 

 2 to 3 per cent, of fat.* 



It is a somewhat viscid fluid, and readily coagulates 

 on standing. As much as 6 litres of it have been dis- 

 charged from a wound of the duct in the course of a day, 

 and it can readily be imagined how in such circum- 

 stances a patient emaciates rapidly and suffers severely 

 from thirst. 



Bacteriology of the Bowel. 



Bacteria of all sorts are, of course, constantly being 

 swallowed with the food. Of these a certain number 

 are destroyed in the stomach, but a considerable quantity 

 run the gauntlet of the gastric juice, and reach the 

 intestine. The number and variety of these will 

 naturally vary considerably with the character of the 

 diet, and also, it would seem, with the locality in which 

 the individual happens to live.t That their presence is 

 not essential to normal digestion is shown by the fact 

 that animals can be reared on sterile food, and also that 



* Carlier, Brit. Med. Journ., 1902, ii. 175 ; and Veau, Gaz. dea 

 Hop., October 30, 1906 (?), p. 1205. 



t Bruini, Archiv f. Verdauungskrankh, 1905, xi. 162. 



