VOL. LXXXV.] PHILOSOPHICAL TKANSACTIONS. 521 



that if the same preparations had been shown to the Abbe Fontana, he would 

 have seen in the new formed substance a continuation of the winding parallel 

 fibres, agreeable to the result of his own experiments. 



Such a contrariety of opinions determined me to decline an appeal so unde- 

 cisive, and to submit my inquiries to a test less doubtful and fallacious : and as 

 such a test was not to be found within the pale of anatomy, I resolved to try 

 whether the resources of physiology could not furnish me with what I wished. 

 From physiology we learn, that if the action of a nerve be suspended by a divi- 

 sion of it, and if that action be recovered in consequence of a union of its 

 divided extremities, such medium of union must possess the characters and pro- 

 perties of nerve. I had therefore only to determine, what nerves appeared the 

 most favourable for the experiment, and pursue the position just stated to its 

 ultimate consequence. I know not whether my choice was judicious, but I de- 

 termined on the 8th pair. The first step I took in this inquiry, was to ascertain 

 what effects will arise from the division of both of these nerves, together with 

 that branch of the great sympathetic nerve accompanying and strongly adhering 

 to them. 



Exper. ] . A dog being properly secured, and a convenient incision made on 

 the fore part of the neck, I divided both the nerves of the 8th pair : he became 

 immediately restless and uneasy, betraying symptoms of great distress on the 

 stomach, which continued 8 hours, when he died. Though the result of this 

 experiment is perfectly agreeable to what other experimental physiologists have 

 stated, I thought it of importance to the present inquiry, to give it confirmation 

 by further experiment. I therefore repeated it on 2 other dogs, one of which 

 survived it 3 days, the other only 2. From these experiments we learn, that the 

 action of these nerves was suspended, and that those vital organs which received 

 their nervous energy from this source, had their functions arrested, so that death 

 followed as a necessary consequence. It may be said here, by way of objection, 

 that a violent shock had been suddenly given to the machine ; and that tiie ani- 

 mal perished rather from the sudden deprivation of the nervous influence, than 

 from its absolute loss ; and that if the same quantity had been abstracted in a 

 more gradual way, the animal might have survived it. How little validity there 

 would be in such an objection, the following experiment will evince. 



Exper. 2. Another dog being procured, I divided only 1 of the nerves of the 

 8th pair. I was surprised to see how slightly he was affected from it ; for, ex- 

 cepting a little moroseness, there was scarcely any alteration perceptible, so that 

 in a few hours after the operation he took food as usual. On the 3d day, I 

 divided the other nerve ; but the same symptoms immediately supervened here 

 as followed the division of both nerves in the former experiments; he continued 

 in a state of restlessness and anxiety, with palpitations and tremors, till the 4th 



VOL. XVII. 3 X 



