VOL. LXXXV.] PHILOSOPHICAL TRANSACTIONS. 517 



sunk to 80 in a minute, respiration as before. At the end of 15 minutes, the 

 pulse was again 120, respiration not altered. The operation was performed 

 about 2 in the afternoon, at Mr. Hunter's, in Jermyn-street. At a of an hour 

 after 5, the respirations were increased to 15 in a minute; the pulse beating 80 in 

 the same time, and very regularly; the breathing seemed so free, that he had 

 the appearance of a dog asleep. At a J- before 8, the pulse beat 80, respirations 

 being 10 in a minute. At f of an hour after 10, respiration was 8 in a minute, 

 the pulse beating 60. The animal heat was exceedingly abated: I applied heat 

 to the chest, he breathed stronger, and raised his head a little, as if awaking 

 from sleep. At J- after 12, Mr. Hunter saw him; the breathing was strong, 

 and 12 in a minute, the heart beating 48 in the same time, slow, but not feeble. 

 He shut his eyelids when they were touched; shut his mouth on its being opened; 

 he raised his head a little, but as he had not the use of the muscles which fix the 

 chest, he did it with a jerk. Mr. Hunter saw him again between 4 and 5 o'clock 

 in the morning; his respirations were then 5 in a minute, the heart beating ex- 

 ceeding slow and weak. We suppose he died about 6 in the morning, having 

 survived the operation l6 hours. This experiment I made from the suggestion 

 of Mr. Hunter, with a view to obviate the objections raised against the reason- 

 ing drawn from the first 3 experiments. It was urged, that though by these ex- 

 periments I had deprived the thoracic and abdominal viscera of their ordinary 

 connection with the brain, yet as the intercostals communicated with all the 

 spinal nerves, some influence might be derived from the brain in this way. This 

 experiment removed all the spinal nerves, and consequently this objection. 



As I found, by the last 2 experiments that dividing the spinal marrow in the 

 lower part of the neck did not immediately kill, though instant death was uni- 

 versally known to be the consequence of dividing it in the upper part of the 

 neck, I expressed my surprise to Mr. Hunter, that the spinal marrow should, 

 according to modern theory, be so irritable in the one place, and so much less 

 so in the other. He told me, that from the time he first observed, that men 

 who had the spinal marrow destroyed in the lower part of the neck lived some 

 days after it, he had established an opinion, that animals which had the spinal 

 marrow wounded in the upper part of the neck, did not die from the mere 

 wound; but that in dividing it so high, we destroyed all the nerves of the 

 muscles of respiration, and reduced the animal to the state of one hanged; 

 whereas in dividing it lower, we still left the phrenic nerves, and allowed the 

 animal to breathe by his diaphragm. If this opinion be well founded, though 

 dividing the spinal marrow in the lower part of the neck does not kill instantly, 

 wliile the phrenic nerves are untouched; yet if I divide the phrenic nerves first, 

 and then divide the spinal marrow in the lower part of the neck, the consequence 

 I said will be the same as if I divided it in the upper part. 



