Anthropology as an Aid to Moral Science
Appendix 3. (91).
Scarpa, in his work on the structure of bones, reports some experiments on the sensitivity of diseased bones and of the caruncle to which caustics have been applied. The Florentine anatomist, Felice Fontana, offered some explanations for the phenomenon in a letter of September 8th. 180l. He firmly maintained that `only the nerves feel'. Scarpa was of the same opinion, but thought that bones could contain extremely fine nerves. Fontana rejected this, suggesting that the movement was communicated to the neighbouring nerves. He says:
| I do not deny what you have observed, but I wish to offer some observations I have frequently made, and recently confirmed after experiments on two dogs. I have often seen the cranium of animals, and even of human beings, being drilled. If the animal was calm, and felt nothing else, it showed no feeling, but at other times, it frequently showed very acute pain. If the wounds festered and were touched, or caustics applied, pain was clearly visible. This great difference, it seems to me, would be impossible if there were nerves in the bones, because nerves would give constant signs of feeling in response to the caustic, and especially to the drill. Colic once made the lower part of my stomach painfully sensitive to the lightest touch; even a movement of the hair caused pain, but the pain was in my skin, not the hair. An inflamed finger was very painful and I could not bear the nail being touched, although the nail itself was insensitive to caustic if applied gently. When nerves are struck, they can have an almost infinite sensibility: the pain in a tooth or its nerve can become unbearable; even a draught can cause toothache. A tap on an animal's bones or the vessels joined to the bones, which are more abundant and exposed in the caruncle you examined, can spread and be felt in nerves whose sensitivity is heightened by illness. I even believe it possible that when the fluid in the vessels stops flowing, or oscillates slightly, the adjacent nerves feel. Consequently, what we think is feeling in the bones attached to the tendons is only the action of the neighbouring nerve made more sensitive by illness. The same happens when something caustic restricts the flow of blood. |
He suggests that according to his careful experiments the pain could be communicated to the nerves by the dispersion of the fluid which, he maintains, fills the elementary nerve canals. These experiments are discussed by Smit in his work `On the digestive force of all the wounded parts of the animal body'.
I do not know if the letter has ever been published, but I possess a signed copy of it annotated by the author.