There is, however, a power which is superior even to that of the headache; and we must avow to the glory of France, that this power is one of the most recent which has been won by Parisian genius. As in the case with all the most useful discoveries of art and science, no one knows to whose intellect it is due. Only, it is certain that it was towards the middle of the last century that "Vapors" made their first appearance in France. Thus while Papin was applying the force of vaporized water in mechanical problems, a French woman, whose name unhappily is unknown, had the glory of endowing her sex with the faculty of vaporizing their fluids. Very soon the prodigious influence obtained by vapors was extended to the nerves; it was thus in passing from fibre to fibre that the science of neurology was born. This admirable science has since then led such men as Philips and other clever physiologists to the discovery of the nervous fluid in its circulation; they are now perhaps on the eve of identifying its organs, and the secret of its origin and of its evaporation. And thus, thanks to certain quackeries of this kind, we may be enabled some day to penetrate the mysteries of that unknown power which we have already called more than once in the present book, the _Will_. But do not let us trespass on the territory of medical philosophy. Let us consider the nerves and the vapors solely in their connection with marriage. Victims of Neurosis (a pathological term under which are comprised all affections of the nervous system) suffer in two ways, as far as married women are concerned; for our physiology has the loftiest disdain for medical classifications. Thus we recognize only: 1. CLASSIC NEUROSIS. 2. ROMANTIC NEUROSIS. The classic affection has something bellicose and excitable on it. Those who thus suffer are as violent in their antics as pythonesses, as frantic as _monads_, as excited as _bacchantes_; it is a revival of antiquity, pure and simple. The romantic sufferers are mild and plaintive as the ballads sung amid the mists of Scotland. They are pallid as young girls carried to their bier by the dance or by love; they are eminently elegiac and they breathe all the melancholy of the North. That woman with black hair, with piercing eye, with high color, with dry lips and a powerful hand, will become excited and convulsive; she represents the genius of classic neurosis; while a young blonde woman, with white skin, is the genius of romantic neurosis; to one belongs the empire gained by nerves, to the other the empire gained by vapors. Very frequently a husband, when he comes home, finds his wife in tears. "What is the matter, my darling?" "It is nothing." "But you are in tears!" "I weep without knowing why. I am quite sad! I saw faces in the clouds, and those faces never appear to me except on the eve of some disaster--I think I must be going to die."