324: DIGESTION. 



was killed by bleeding, and the contents of the isolated portion 

 of the intestine were examined. The quantity of juice obtained 

 was considerable, being from 1,235 to 1,852 grains for about six 

 and a half feet of intestine. It was always found to be 

 much less when intestinal digestion had been suspended, and 

 its quantity could be increased by the injection into the loop 

 of a little solution of manna, sulphate of soda, or aloes. 

 The fluid thus obtained was clear, a little yellowish, with a 

 saline taste and an alkaline reaction. It was mixed with 

 mucus, which formed a sediment when the fluid was allowed 

 to stand, and could be separated by filtration. 1 



Notwithstanding the care with which these observations 

 were conducted, it is not probable that the fluid thus ob- 

 tained by Colin was the normal intestinal juice ; and it cer- 

 tainly does not correspond in its general characters with the 

 fluids which have been studied by other experimenters. 



It becomes an interesting question, in this connection, to 

 determine whether the solitary and the agminated glands 

 produce any secretion which is discharged into the intestinal 

 cavity. Though these follicles are closed, the observations 

 of Colin have shown pretty conclusively that they are capable 

 of producing a secretion ; but the precise mode of its forma- 

 tion is not so apparent. The experiment by which this was 

 demonstrated was made on a pig, an animal in which there 

 is an enormous agminate gland, ribbon-shaped, and over six 

 feet in length. That portion of the ileum in which the 

 gland is situated was emptied, and about four and a half feet 

 of it isolated by two ligatures from the rest of the canal. At 

 the end of an hour the animal was killed and the intestine 

 examined. The surface of the gland was found covered with 

 a layer of mucus, thicker and more consistent than over other 

 portions of the membrane. 2 The only way in which it could 

 reasonably be supposed that this secretion was produced is by 



1 COLIN, Traile de Physiologic Comparee, Paris, 1854, tonae i., p. 648 et seq. 



2 Loc. tit. 



