After the candles were brought, Kant prosecuted his studies till nearly ten o'clock. A quarter of an hour before retiring for the night, he withdrew his mind as much as possible from every class of thoughts which demanded any exertion or energy of attention, on the principle, that by stimulating and exciting him too much, such thoughts would be apt to cause wakefulness; and the slightest interference with his customary hour of falling asleep, was in the highest degree unpleasant to him. Happily, this was with him a very rare occurrence. He undressed himself without his servant's assistance, but in such an order, and with such a Roman regard to decorum and the _to prepon_, that he was always ready at a moment's warning to make his appearance without embarrassment to himself or to others. This done, he lay down on a mattress, and wrapped himself up in a quilt, which in summer was always of cotton,--in autumn, of wool; at the setting-in of winter he used both--and against very severe cold, he protected himself by one of eider-down, of which the part which covered his shoulders was not stuffed with feathers, but padded, or rather wadded closely with layers of wool. Long practice had taught him a very dexterous mode of _nesting_ himself, as it were, in the bed-clothes. First of all, he sat down on the bedside; then with an agile motion he vaulted obliquely into his lair; next he drew one corner of the bedclothes under his left shoulder, and passing it below his back, brought it round so as to rest under his right shoulder; fourthly, by a particular _tour d'adresse_, he treated the other corner in the same way, and finally contrived to roll it round his whole person. Thus swathed like a mummy, or (as I used to tell him) self-involved like the silk-worm in its cocoon, he awaited the approach of sleep, which generally came on immediately. For Kant's health was exquisite; not mere negative health, or the absence of pain, but a state of positive pleasurable sensation, and a genial sense of the entire possession of all his activities. Accordingly, when packed up for the night in the way I have described, he would often ejaculate to himself (as he used to tell us at dinner)-- 'Is it possible to conceive a human being with more perfect health than myself?' In fact, such was the innocence of his life, and such the happy condition of his situation, that no uneasy passion ever arose to excite him--nor care to harass--nor pain to awake him. Even in the severest winter his sleeping-room was without a fire; only in his latter years he yielded so far to the entreaties of his friends as to allow of a very small one. All nursing or self-indulgence found no quarter with Kant. In fact, five minutes, in the coldest weather, sufficed to supersede the first chill of the bed, by the diffusion of a general glow over his person. If he had any occasion to leave his room in the night-time, (for it was always kept dark day and night, summer