The reader will see, as we proceed, that boast as doctors often will of _their_ cures, as if they were wholly theirs, this _vis medicatrix naturæ_ is the chief doctor after all; and she, good, kind angel, hovering over the bed of sickness, without fee, and often without even any acknowledgment of her services, saves the life of many a poor patient, who is near being drugged to death by some ignorant quack, or some over-dosing doctor. That the reader may be somewhat acquainted with the extent of the influence which this curative principle exerts, I will cite some examples of its operation. If some offending substance be present in the stomach, vomiting is produced, the substance is evacuated, and this organ, having thus relieved itself by an effort of nature, as it is commonly expressed, now goes on with the performance of its usual functions. In this case, the ordinary action of the organ is entirely reversed, in obedience to the curative principle. If an attempt be made to allay the vomiting before the offending substance is thrown off, it is an injurious interference with a salutary effort. Sometimes the effort is ineffectual, and needs the assistance of art. It is often difficult to decide whether vomiting is prompted by this curative principle, or is caused by irritation, which should be quieted by medicine. Want of due discrimination, either from lack of knowledge, or from carelessness, very often leads to errors on this point. The operation of this principle is beautifully exhibited in the succession of the processes of inflammation. You see a swelling. It, after a while, begins to soften. There is matter in it, but it is not yet very near the surface. But soon, at some point, it comes nearer and nearer to the surface, the wall of the abscess thus becoming constantly more thin, till, at length, it opens and discharges. The discharge continues till the swelling is nearly all gone, and the remainder is absorbed, and the part is restored to its natural state.