To take sleep first, it should be a condition as automatic as breathing, but by its very nature, by the fact that, in order to arrive at it, both body and mind must pass into and through a quiescent state, so that the condition of unconsciousness may naturally come, it has many more foes than the mere taking and expelling of breath. A severe pain in the foot or any remote organ of the body will make sleep difficult, if not impossible, until exhaustion has come, whereas such a pain would not in any way prevent breathing; or, again, any anxiety or tension of mind will hinder sleep. Continued pain, of course, results in bodily exhaustion, continued anxiety in the corresponding exhaustion of the mind, the inability to _think_ longer; but these are rather special causes of sleeplessness, which are responsible for a comparatively small percentage of those patients--for they are no less--who habitually sleep badly, either finding difficulty in getting to sleep, or awaking at timeless hours, or awaking, not to sleep again, in very early hours of the morning. These, though one can class all under the general heading of bad sleepers, are divisible into at least two distinct classes, while insomnia may arise from very different causes. Certain general rules apply to everyone in the regulation of the bedroom, and though confirmed bad sleepers may scoff at the notion of furniture and bedgear having anything to do with their own particular thorn in the flesh, it will at any rate be harmless for them to know how a bedroom can be regulated in order to give the best possible conditions.