differ from each other only by a single letter, the one passes over to the other.” We are seized with compassion for human nature and for ourselves, when we find him relating that a knight who suffered from the stone always, if he dreamed of food, had an attack on the following day, and adding _cibos enim et dolores degustare dicimus_--as though nature were in the habit of amusing herself by making puns in Latin. Yet this was the man who had intuitively divined the admirable theory of painful sensations in sleep already alluded to, and who, a physician, and one of no mean distinction, had clearly conceived the sympathetic action of the solar plexus. Newton himself can scarcely be said to have been sane when he demeaned his intellect to the interpretation of the Apocalypse, or the horns of Daniel; nor, again, when he wrote to Bentley, “By means of the law of attraction, one can very well understand the elongated orbits of comets; but as to the nearly circular orbits of planets, I see no possibility of obtaining their lateral difference, and this can only be accomplished by God.” Yet in his _Optics_, Newton had inveighed against those who, after the manner of the Aristotelians admit occult properties in matter, thus arresting the researches of natural philosophers, without leading to any conclusion. In fact, a century later, the true cause, which had escaped Newton’s observations, was discovered by La Place. Ampère believed, in all sincerity, that he had found the method of squaring the circle. Pascal, though he had been the first to study the laws of probability, believed that the touch of a relic had power to cure a lachrymal fistula--a statement which he printed in one of his works. Rousseau makes of his own maniacal savagery the ideal type of man, and believes that every natural production, if agreeable to the sight or taste, must be innocuous, so that arsenic, according to him, could not be harmful. His life is made up of contradictions: he prefers the country, and lives in the Rue Platonière; he writes a treatise on education, and sends his children to the foundling hospital; he adjudicates on the claims of the various religions with the acuteness of an unbiassed sceptic, and throws stones at trees in order to divine the future and decide the question of his own salvation; nay, he writes to the Deity, and lays his letters on the altars of churches, as though they were His exclusive abode.