Without for the moment taking into consideration those millions of London who stifle in crowded slums, on insufficient or unsuitable food, and many of whom have inherited from birth some taint of constitution, and concerning ourselves for the moment only with those within whose reach, broadly speaking, are all the expedients known for insuring health, we should find it curious and probably depressing to ascertain, if we could, what proportion _felt well_, given they had no definite cause of ill-health which it was out of their power to remove. Many would put down their comparatively lower level of health while living in London to the fact that they were working hard. This, if true, is a sad and sobering reflection, since it would seem to imply that Nature had not designed the average healthy individual to work hard; and though it is probably infinitely better that people should work hard, and feel slightly below par all the time, than that they should devote their whole time to keeping well, yet it would be unsatisfactory if we were forced to believe that continued hard work cannot be compatible with continued good health. Many again would say that they never feel well without exercise, and that it is impossible to get exercise in London. That they can get sufficient exercise anywhere, with a very small expense of time, we hope to show in a later chapter; but, in the meantime, have such tried deliberately and unswervingly to eat far less than they feel inclined, or to use some sort of definite selection in the matter of what they eat? Others again would (quite rightly) put down their slight but chronic indisposition to an absence of air; such perhaps do not know what an immensely increased supply of air everyone can get by always keeping bedroom windows wide open. Now to many such the idea of using training as a means of merely keeping well is probably novel. They are accustomed to feel slightly unwell--that perhaps is too strong a term--when they are in a town and at work, and having always felt thus have acquiesced in what we may call a vicious habit. But they have always understood training to mean a _régime_ of fixed exercise (founded on beefsteaks), which is as impossible for them as it would also be unsuitable for them; or, in a modified form, twenty minutes or half an hour with dumb-bells every morning and evening. Many have probably tried dumb-bells; some, no doubt, reap considerable benefit from their use, but not a few, and both the present writers are among them, after giving them a good trial, loathe the sight of them. And numbers, in such a case, have abandoned themselves, with more or less content, to continuing to feel slightly below par, and praying for the holidays.