30 were greatly improved or showed some improvement. 17 exhibited no change. 2 died in status epilepticus. =Traumatic insanity.= Traumatic insanity is closely allied to traumatic epilepsy, occurring, as a general rule, late in the history of the case, when the frequency of the fits and the associated disturbance of the higher faculties breaks down the mental and moral control of the patient. The particular form of insanity varies according to the circumstances of the case. Kraft Ebbing reported on 42 cases, the disease partaking of the following types:-- 18 cases of mania. 13 cases of dementia. 5 cases of dementia with epilepsy. 3 cases of general paralysis. 3 cases of melancholia. Of 104 cases reported by Christian, 16 were of dementia. 29 of mania. 47 of general paralysis. 12 were of epilepsy. Mania--of a violent type--usually develops within a short time of the accident--a few hours or days. Its development is probably dependent on an _acute cerebral œdema_--the result of a most severe grade of vaso-motor depression--and it is often, though not necessarily, associated with extensive cerebral injury. There is marked engorgement of the cerebral venous system, and considerable increase of cerebro-spinal fluid, both on the surface of the brain and in the ventricular spaces. When insanity develops at a later date, of whatever variety, it is probably dependent on definite pathological changes. Ll. Powell, Duret, and others, after investigating the conditions, came to the conclusion that the injury was comparatively superficial--subdural cysts and hæmatomata, pachymeningitis, osteosclerosis, ossification of the dura mater, &c. They also maintain--an opinion that I also hold--that the nervous phenomena are, in most cases, due to reflex meningeal irritation. Ll. Powell reports on 67 cases submitted to operation, with the following results:-- In 41 there was mental recovery. 12 there was marked mental improvement. 5 there was slight mental improvement. 4 there was no change. Death resulted in 5 cases. The results obtained by surgical treatment are largely dependent on the time that has elapsed since the accident. Lapse of time is no bar to operation, but the sooner this procedure is carried out the better for the patient. =Treatment.= I think that it must be accepted that, without surgical interference, the prognosis is of the most unfavourable type. These cases, if left to themselves, drift into the public and private lunatic asylums, there remaining to the end, hopeless wrecks.