A lady, previous to an attack of sciatica, dreamed that she had caught her foot in a spring-trap, and that before she could be freed it was necessary to amputate the member. The operation was performed; but as she was released, a large dog sprang at her and fastened his teeth in her thigh. She screamed aloud and awoke in her terror. Nothing unusual was perceived about the leg; but, on getting up in the morning, there was slight pain along the course of the sciatic nerve, and this before evening was developed into well-marked sciatica. Insanity is frequently preceded by frightful dreams, and I have advanced several examples to this effect from the experience of others. We should naturally expect that very often the first manifestations of a diseased brain should appear during sleep. But dreams are of such a varied character, and so thoroughly irreconcilable with the normal mental phenomena of the wakeful state, that it is difficult to say that such or such a dream is evidence of a diseased mind. As, in some of the cases I have brought forward, a dream may take so firm a hold of the reason as to be the exciting cause of insanity, and not simply a sign of its approach, I am disposed, from my own experience, to regard the frequent repetition of the same dream as often indicative of a disordered mind, when very close observation would fail to reveal other evidences. There are, however, exceptions to this statement, as has been shown in the previous chapter. Several cases, in which insanity was preceded by terrifying dreams, have come under my observation. In one of them a lady dreamed that she had committed murder, under circumstances of great atrocity. She cut up the dead body, but could not, with all her efforts, divide the head, which resisted her blows, with an axe and other instruments. Finally she filled the nose, eyes, and mouth with gunpowder, and applied a match. Instead of exploding, smoke issued slowly from the orifices of the skull, and was resolved into a human form, which turned out to be that of a police officer sent to arrest her. She was imprisoned, tried, and sentenced to execution, by being drowned in a lake of melted sulphur. While the preparations were being made for the punishment she awoke. She related the particulars of her dream to several friends, but it apparently made no great impression on her mind. The next night she dreamed of somewhat similar circumstances, and for several nights subsequently. On the sixth day, without any premonition, she attempted to kill herself by plunging a pair of scissors into her throat, and since that time to her death, which took place a few months subsequently, was constantly insane.