The human body, if it is to be maintained in but a fair state of health, requires a certain amount of fresh air--a certain amount of flesh-forming, bone-forming, brain-forming, and warmth-giving nutriment. Our girls require to have a tolerable, if not exactly a faultless, circulation, in order that these various foodstuffs may be digested, _i.e._, converted into these flesh, bone, and brain-forming tissues. In order to have a tolerable circulation, the body must have a regular amount of exercise and of fresh air. There, in a nutshell, is the secret of the whole matter. Given a fairly normal state of health to begin with, that health may be maintained by a little wise direction of our actions towards supplying the really very moderate demands of Nature, upon which, however, modest as they are, she insists, to enable her to carry on the process of healthy life. Deprive her of that little, and the results are such as we too frequently see--broken-down health from overwork (so-called) of many of our busy sisters. It is our intention here to endeavour to put this plainly before our girls. We will imagine, then, that some of our girls have to pass many--say eight or ten--hours of their days in work; that that work is sedentary work; that our girls are very apt to stoop, for their poor backs get weary sometimes. We will imagine that it is winter, and sitting as they do all day, they like to have all the windows closed. Our girls will not feel very hungry when meal-time comes, especially if they have to provide their own meals. In fact, many of our girls practise a little economy in this direction, if the choice of doing so rests with them. Economy, we all know, is imperative in many conditions of life--not only amongst working girls; and it is a serious matter to practise it wisely--to determine and mark clearly the line that divides the luxuries from the necessities. In the former practise as much economy as you will; in the latter it is only a false way of meeting matters which will have to be balanced by-and-by with heavy interest.