VOL. LXXXV,] PHILOSOPHICAL TRANSACTIONS. 515 



them to the bottom in water. The trachea was not inflamed. The nerves of 

 the right side, from which a portion had been cut out, seemed to have undergone 

 little alteration ; they were only a little more vascular than usual, and had the 

 rounded swell where they had been divided. The nerves of the left side, which 

 had retracted but little, and had been only divided, had their extremities covered 

 with a plug of coagulable lymph. I suspected that the reason of the first dog's 

 dying so soon, was, that none of the nerves had yet acquired the power of per- 

 forming their former ofiices; and that, were the operations performed at a 

 greater distance of time, the animal would recover. With this idea, I was led 

 to repeat my experiments, allowing a greater interval to take place between the 

 first and second. 



Exper. 4. March 6th, I repeated experiment I, on a large dog. His eye on 

 the right side seemed instantly affected, looked dull aud inflamed; he coughed 

 and breathed with some difficulty; the secretions from the salivary glands were 

 much increased; he had tremors; these however I attributed partly to fear, as on 

 caressing him they disappeared. He ate and drank very well, and had stools. 

 Most of these symptoms continued but a few days, the eye becoming more 

 clear, and the difficulty of breathing hardly perceptible; he vomited, but only 

 after eating, a circumstance which often takes place in dogs in perfect health, 

 from devouring their food too greedily. Thus he continued for 3 weeks; the 

 external wound had healed, almost by the first intention; he ate greedily, and 

 had perfectly recovered: I supposed the regenerated nerves might now be per- 

 forming their offices. 



Exper. 5. March 27th, I repeated experiment 2 on the same dog, but did 

 not remove quite so much of the nerves. He was stupid for a minute or 2, and 

 gaped for breath ; but in a few minutes more these symptoms went off"; in a J- 

 of an hour after he ate some boiled meat, with his usual avidity; all the symp- 

 toms of the preceding operation again took place, and in the same order. The 

 vomiting and difficulty of breathing were rather more considerable; he ate and 

 drank however, and had stools. The convulsive jerks of the abdominal muscles, 

 which hardly took place in the last experiment, were observed in this, during ex- 

 piration, but were not constant, as in the first dog. On the 15th of April he 

 was nearly as well as before the operations, only he was leaner, and perhaps 

 weaker, from the confinement, as well as from the operations. I wished to see 

 the state of the nerves; an artery was opened in the groin, and the animal ex- 

 pired in a few seconds. In examining the dead body, the viscera were all to ap- 

 pearance sound. The divided nerves of the right side were firmly united; having 

 their extremities covered with a kind of callous substance; the regenerating 

 nerve, like bone in the same situation, converting the whole of the surrounding 

 extravasated blood into its own substance. The nerves of the left side were also 



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