“You know the cold bath has long been in vogue here as a tonic; but the shock of the cold water has always appeared to me, generally speaking, as too violent, and I have found it much more agreeable to my constitution to bathe in another element, I mean cold air. With this view I rise almost every morning and sit in my chamber, without any clothes whatever, half an hour or an hour, according to the season, either reading or writing. This practice is not in the least painful, but, on the contrary, agreeable; and if I return to bed afterwards, before I dress myself, as sometimes happens, I make a supplement to my night’s rest of one or two hours of the most pleasing sleep that can be imagined. I find no ill consequences whatever resulting from it, and that at least it does not injure my health, if it does not in fact contribute much to its preservation. I shall therefore call it for the future a _bracing_ or _tonic_ bath.” (Bigelow’s Works of Franklin, vol. iv. p. 193.) Some years afterwards, while in Paris and suffering severely from gout in his foot, he used to expose the foot naked out of bed, which he found relieved the pain, because, as he supposed, the skin was given more freedom to act in a natural way. His remarks on air-baths were published in the early editions of his works and induced many people to try them. Davis, in his “Travels in America,” says that they must have been suggested to him by a passage in Aubrey’s “Miscellanies;” but, after searching all through that old volume, I cannot find it. Franklin, however, made no claim to a discovery. Such baths have been used by physicians to strengthen delicate persons, but in a more guarded and careful manner than that in which Franklin applied them. It was characteristic of his genial temperament that he loved to dream in his sleep and to recollect his dreams. “I am often,” he says, “as agreeably entertained by them as by the scenery of an opera.” He wrote a pleasant little essay, addressed to an unknown young lady, on “The Art of Procuring Pleasant Dreams,” which may be said to belong among his medical writings. Fresh air and ventilation are the important dream-persuaders, and bad dreams and restlessness in bed are caused by excess of perspirable matter which is not allowed to get away from the skin. Eat less, have thinner and more porous bedclothes, and if you are restless, get up, beat and turn your pillows, shake all the sheets twenty times, and walk about naked for a while. Then, when you return, the lovely dreams will come.