ON THE ORGANIC FUNCTIONS. 871 



the tissue?. When irritation is applied to them, it causes increased activity 

 of all the nutritive changes, cell-growth in particular taking place with ab- 

 normal rapidity. On the contrary their paralysis, as by section, leads to 

 diminished activity in the nutritive operations, and atrophy. In proof of 

 these statements Samuel adduced the results of many experiments showing 

 that if a rough fragment of bone be passed beneath the sciatic nerve stretch- 

 ing it like a cord and producing continual irritation of its fibres, the thigh, 

 leg, and foot swell in the course of 24 or 36 hours. The whole limb below 

 the seat of irritation of the nerve becomes hypersesthetic, its temperature 

 rises, and an ill-smelling discharge takes place from the wound, all circum- 

 stances indicating the increased activity of the various processes both of nu- 

 trition and disintegration. In like manner laryngitis may be produced by 

 irritating the superior laryngeal nerves, and after death the mucous mem- 

 brane is found swollen and reddened ; so by irritation of the Vagi, just below 

 their exit from the skull, the symptoms and pathological conditions charac- 

 terizing pneumonia may be obtained, and by irritating the spinal cord with 

 a bristle dipped in croton oil passed through it in such a direction as to 

 affect the posterior roots of the spinal nerves at the level of the last dorsal 

 vertebra, he observed great hypenemia, tumefaction, and elevation of tem- 

 perature in the lower limbs. 1 Dr. Axmann found that when the spinal nerves 

 of frogs were divided on the distal side of their prevertebral ganglia, the 

 nutrition of the parts supplied by them was much more injuriously affected 

 than it was when the section was made between the ganglia and the spinal 

 cord. A large number of pathological cases are on record which certainly 

 appear to support the views of Samuel. One of the most typical is that 

 given by Sir James Paget in his lectures on Nutrition, on the authority of 

 Mr. Hilton : " A man was at Guy's Hospital, several years ago, who, in 

 consequence of fracture of the lower end of the radius, repaired by an ex- 

 cessive quantity of new bone, suffered compression of the median nerve. He 

 had ulceratiou of the thumb, and of the fore and middle fingers, which had 

 resisted various treatment, and was cured only by so binding the wrist, that 

 the parts on the palmar aspect being relaxed, the pressure on the nerve was 

 removed. So long as this was done, the ulcers became and remained well ; 

 but as soon as the man was allowed to use his hand, the pressure on the 

 nerves was removed, and the ulceration in the parts supplied by it returned." 2 

 In the American war a special Hospital having been set aside for injuries 

 and diseases of nerves, the surgeons, Messrs. Mitchell, Morehouse, and Keen, 

 had large opportunities of observing the effects of such lesions. The condi- 

 tions they found to occur in the parts below the seat of injury were atrophy 

 of muscles, and various subacute inflammatory states indicated by tumefac- 

 tion and congestion, oedema, thickening of the cuticle and glossiness of the 

 skin, cracks and fissures in it, bed-sores, eczema, curved and taloulike nails, 

 retraction of the skin of the ungual phalanx and exposure of the matrix, 

 painful swelling of joints and altered or arrested secretions (Sweat). Biiren- 

 spruug again has satisfactorily shown that in some cases of Herpes, at least, 

 the ganglia on the posterior roots of the spinal nerves are inflamed, and 

 Vandyke Carter 3 has pointed out that in cases of leprosy the cutaneous 



1 See also for corroborative experiments, Lahorde and Leven, Gaz. Medicale, 1870 ; 

 Vulpian, Brown Sequard's Archives, 1872. p. 384. 



2 Similar cases are ^iven by M. Gillette in the Dictionnaire Encyclopediqtie, by M. 

 Charcot in Brown-Sequard's Archives de Fhysiologie, and Mr. 1'Anson, Lancet, 

 1871, vol. ii, p. 913; by Hutchinson, in the London Hospital Reports for 1866; by 

 Schiefferdecker, Edis, and a storehouse of such facts in the work of Messrs. Mitchell, 

 Morehouse, and Keen, On Gunshot Wounds and other Injuries of Nerves. 



3 British'and For. Med.-Chir. Rev., 1803, January. 



