A necessity, more painful to me by far than that of taking continued exercise, arose out of a cause which applies, perhaps, with the same intensity only to opium cases, but must also apply in some degree to all cases of debilitation from morbid stimulation of the nerves, whether by means of wine, or opium, or distilled liquors. In travelling on the outside of mails, during my youthful days, for I could not endure the inside, occasionally, during the night-time, I suffered naturally from cold: no cloaks, &c. were always sufficient to relieve this; and I then made the discovery that opium, after an hour or so, diffuses a warmth deeper and far more permanent than could be had from any other known source. I mention this, to explain, in some measure, the awful passion of cold which for some years haunted the inverse process of laying aside the opium. It was a perfect frenzy of misery; cold was a sensation which then first, as a mode of torment, seemed to have been revealed. In the months of July and August, and not at all the less during the very middle watch of the day, I sate in the closest proximity to a blazing fire; cloaks, blankets, counterpanes, hearthrugs, horse-cloths, were piled upon my shoulders, but with hardly a glimmering of relief. At night, and after taking coffee, I felt a little warmer, and could sometimes afford to smile at the resemblance of my own case to that of Harry Gill. [Footnote: 'Harry Gill:'--Many readers, in this generation, may not be aware of this ballad as one amongst the early poems of Wordsworth. Thirty or forty years ago, it was the object of some insipid ridicule, which ought, perhaps, in another place, to be noticed. And, doubtless, this ridicule was heightened by the false impression that the story had been some old woman's superstitious fiction, meant to illustrate a supernatural judgment on hard-heartedness. But the story was a physiologic fact; and, originally, it had been brought forward in a philosophic work, by Darwin, who had the reputation of an irreligious man, and even of an infidel. A bold freethinker he certainly was: a Deist, and, by public repute, something more.] But, secretly, I was struck with awe at the revelation of powers so unsearchably new, lurking within old affections so familiarly known as cold. Upon the analogy of this case, it might be thought that nothing whatever had yet been truly and seriously felt by man; nothing searched or probed by human sensibilities, to a depth below the surface. If cold could give out mysteries of suffering so novel, all things in the world might be yet unvisited by the truth of human sensations. All experience, worthy of the name, was yet to begin. Meantime, the external phenomenon, by which the cold expressed itself, was a sense (but with little reality) of eternal freezing perspiration. From this I was never free; and at length, from finding one general ablution sufficient for one day, I was