In young girls there often is a proneness to be excited by slight causes,—to be startled by mere trifles. Savarry tells us of a man who, at two o’clock each day, was irresistibly impelled to rap at doors and make very odd noises, and felt intense pleasure in doing this. If this had occurred in the night, it would have been termed somnambulism. Gall also relates of a young man at Berlin, who, after rolling about in his bed for some time, and jumping out and in repeatedly in his sleep, at last started up awake, astonished at the crowd around his bed. And Dr. Darwin writes of a boy, nine years old, who went through a course of gymnastics, with an occasional song between the acts. At length he seemed bursting, and soon sank down in a stupor. ASTR. I have read, (I think in Mezeray,) of an epidemic mania of this sort, in which the creatures tore off their clothes, and ran naked through the streets and churches, until they fell breathless on the ground. Some of them swelled even to _bursting_, unless they were bound down by cords. The disease was referred to the agency of demons, and treated by exorcisms; they even tore their flesh to free themselves from their possessing devils. I have seen also a confident story of some nuns, who jumped so high during an hysteric ecstacy, that they were at length seen to fly; in imitation, perhaps, of the Corybantes, the priests of Cybele, who, in the celebration of their mysteries, leaped and raved, like madmen in the midst of their shrieks and howlings. EV. All these eccentricities amount to complete monomania for the time they last, and they are marked often by a very violent _imitative_ propensity; like the delirium which came upon the Abderites, on witnessing the performance of the “Andromeda” of Euripides, by Archelaüs. Of such nature was the “_dancing mania_” of the middle ages; the _tarantula_ of Apulia, in which melancholy was succeeded by madness; the feats of the _Jumpers_ of Cornwall, and the _Convulsionnaires_ of the Parisian miracles. Yet with all this apparent violence, there might be a power of control by management. On some sudden and extreme mental influence, there was in the Maison de la Charité, at Haerlem, an infectious convulsion of this nature, so that the troop of little scholars, girls and boys, were a mere legion of dancing maniacs; and nothing appeared to relieve them, until a ruse of the physician Boërhave put to flight the illusion. With a solemn voice he pronounced, in the hearing of the little creatures, his decision that each of them should be burned to the bone of the arm with a red hot iron. From that moment the mania subsided. Dr. Hecker, in his account of the _Dance_ of the middle ages, notices two forms of this national monomania:—“_Tarantulism_,” and the “_Danse de Saint Guy_.” The first was marked by all sorts of illusions, demonomania, obscene dancing, groaning, and falling down senseless.