MOIIEAU'S EXPERIMENT. 363 



part, but took care to leave all the blood-vessels uninjured. He 

 next tied off in the same way a piece of intestine about the same 

 length as the first on each side of it, but did not cut the nerves 

 going to tliem. All the three parts were thus completely 

 empty ; they were all equally isolated from the rest of the 

 intestine, and were all in exactly the same condition in regard 

 to their vascular supply; but the nerves of the middle piece 

 were cut, and tlierefore paralysed, while those of the pieces at 

 each side of it were not. He then put the intestine back into 

 the abdomen, and sewed up the wound. After four or five 

 hours, he killed the dog, and examined the intestine. The two 

 pieces which liad been ligatured off from the rest, but whose 

 nerves liad not been cut, were found empty, just as they were 

 when they were put into the abdomen : but the third piece, 

 which lay between the two others, and whose nerves had all 

 been divided, was found distended like a sausage with a fluid 

 whose composition, as I have already said, was almost identical 

 with that of cholera-stools. ISTow, in this experiment, all the 

 nerves going to the intestine were cut, and therefore paralysed ; 

 but we do not know whether or not the same effects would have 

 been produced if only some of them had been paralysed, and it 

 is not improbable that it might have been so. 



We have, then, in cholera, the same profuse secretion as in 

 Morcau's experiment ; and from identity of effect we may fairly 

 infer identity of cause, and are, therefore, justified in concluding 

 that the great outpouring of fluid into the bowel is due in both 

 cases to paralysis of some, at least, of the nerves of the intestine. 

 The probability that only some of the nerves, and not all of them, 

 are paralysed in cholera, is strengthened by a consideration of 

 the circumstances which induce a paralytic secretion of saliva in 

 the submaxillary gland. Whenever a difficult question regard- 

 ing secretion arises, we are always obliged to refer to this gland, 

 because in it the process of secretion has been most fully investi- 

 gated, and the conditions under which it takes place are best 

 understood. When some of the nerves connected with the sub- 

 maxillary gland* are paralysed by dividing them, a continuous 

 and profuse secretion is poured out by it. When some addi- 



* The fibres connecting the submaxillary gnnglion and Ibe lingual nerve. 



