NEUROTOMY. , 57 



He found that, partly from the faulty construction of the shoe, and more from 

 the premature and cruel exaction of labour, the horse was subject to a variety 

 of diseases of the foot : all of them accompanied by a greater or less degree 

 of pain— often of a very intense nature, and ceasing only with the life of the 

 animal. 



He frequently met with a strangely formidable disease, in what was called 

 "coffin-joint lameness," but to which Mr. James Turner afterwards gave the 

 very appropriate name of "navlcular-joint disease." It was inflammation of 

 the synovial membrane, either of the flexor tendon or navicular bone, or both 

 where the tendon plays over that bonej and it was accompanied by pain' 

 abrasion, and gradual destruction of these parts. 



For a long time he was foiled in every attempt which he made to remove or 

 even to alleviate the disease. At length he turned his thoughts to the pro- 

 bability of subduing the increased sensibility of the part, by diminishing the 

 proportion of nervous influence distributed on the foot. He laid bare one of 

 the metacarpal nerves, and divided it with a pair of scissors. There was always 

 an immediate and decided diminution of the lameness, and, sometimes, the horse 

 rose perfectly sound. This happy result, however, was not always permanent, 

 for the lameness returned after the lapse of a few weeks, or on much active 

 exertion. He next cut out a small piece of the nerve. The freedom from 

 lameness was of longer duration, but it eventually returned. 



He then tried a bolder experiment. He excised a portion of the nerves 

 going both to the inner and outer metacarpals. We transcribe his own account 

 of the result of the first ease of complete neurotomy — excision of the nerve 

 on both sides of the leg — that ever was performed. 



" The animal, on rising, trotted boldly and without lameness, but now and 

 then stumbled with the foot operated on. The wounds healed in a few days, 

 and the patient was put to grass. Some weeks afterwards a favourable account 

 was received of her soundness; but she was soon brought again to us, on 

 account of a large sore on the bottom of the foot operated on, and extending 

 from the point of the frog to the middle and back part of the pastern. The 

 mare, in galloping over some broken glass bottles, had placed her foot upon a 

 fragment of the bottom of one of them, and which had cut its way through the 

 frog and tendon into the joint, and stuck fast in the joint for some seconds, 

 while the animal continued its course apparently regardless of injury. The 

 wound bled profusely, but the mare was not lame. Many days had elapsed 

 before I saw her, and large masses of loose flesh were cut from the edges of the 

 wound, without the animal showing the slightest sign of suffering pain. The 

 processes usually attending sores went on, with the same appearances that took 

 place in sores of parts not deprived of sensibility. Such extensive injury, how- 

 ever, had been done to the joint as rendered the preservation of free motion in 

 it very improbable, even were the opening to close, which was a matter of 

 doubt, and therefore she was destroyed. It appeared clearly from this, that 

 by the destruction of sensibility the repairing powers of the part were not injured; 

 but that the natural guard against injury being taken away by the division of 

 both the nerves, an accident was rendered destructive which, in the usual con- 

 dition of the foot, might have been less injurious*." 



The cut in the next page gives a view of the nerve on the inside of the leg, as 

 it approaches the fetlock. It will be seen that branches are given off above 

 the fetlock, which go to the fore part of the foot and supply it with feeling. The 

 continuation of the nerve below the fetlock is given principally to the quarters 

 and hinder part of the foot. The grand consideration, then, with the operator 

 is— does he wish to deprive the whole of the foot of sensation, or is the cause 

 * Veterinarian, vol. ix. p. 363. 



