While, then, I entirely agree with public opinion in attaching great importance to the proper regulation of the bowels, and in tracing much suffering to their neglect, I am only the more anxious that we should, as far as possible, follow Nature in our arrangements, and reap the benefit of her aid. If we do so, we shall not only be less frequently obliged to have recourse to medicine, but, by our knowledge of the causes of the deficient action, be greatly assisted in our selection of an appropriate kind of laxative, and thus avoid forcing the constitution too far. It sometimes happens, for example, that, from debility of the muscular coat, the peristaltic motion is insufficient to propel the contents of the intestines, even with the aid of proper diet and exercise. In such cases, small doses of aloes or rhubarb, or other laxatives, which act chiefly by exciting the muscular contraction, will be sufficient to clear the bowels, especially when any mild tonic is conjoined with them; while saline laxatives which act chiefly on the mucous coat, may be given freely, and even cause numerous watery evacuations, and yet the real or solid contents of the intestines continue unremoved. In practice this often happens; and hence the frequent mistake of supposing that there is proper passage from the bowels, when in reality there is no such thing. The period of life at which intestinal inactivity is attended with the most serious consequences, is at and for a few years after puberty. At that age a sudden change is often made from the restless activity of youth to all the stillness of a sedentary profession, without any corresponding alteration being made in the quantity of food consumed. The vigorous appetite, which is perfectly natural during a period of growth and great bodily activity, remains at first unimpaired, and impels the individual to eat an amount of food far beyond the present necessities of the system or the powers of digestion. The consequence is a tendency, not only to fulness from excessive nutrition, but to severe digestive disorder from the stomach and intestines being weakened both by want of exercise and by excess of food. I have known many instances of dyspepsia, constipation, and mental affection, and even of active inflammation, thus produced. In one case, four years of continued bad health in an otherwise sound constitution were the penalty inflicted before the real cause was accidentally discovered. During all that time, too, temporary relief invariably followed the use of purgatives, and seemed in some measure to point to the truth; but from the mind never having been directed to the principles, its practical bearing was overlooked, and now the individual wonders that the cause did not, even at first sight, arrest the attention of his medical advisers.