In the latter part of the nineteenth century, Dr. Bowditch, of Boston, showed that consumption developed most where the surrounding soil was moist, and generally it is the impression that dry air is the only proper air for a consumptive person to breathe. This theory, however, is being rapidly exploded, and patients now remain outdoors in any weather, and no kind of air is objected to by physicians, provided it is outdoor air. Some little time ago the writer was called by a Board of Health to investigate a certain swamp which had some odor, was considered a blot on the landscape in an unusually picturesque village, and was said to be responsible for a long list of contagious diseases. A house-to-house inquiry in the vicinity showed that among some dozen families, only one illness in the last few years could be remembered, and that was an old lady who had been on the verge of the grave for forty years. It is curious to note the many examples which are cited by the earlier sanitarians to prove the dangerous effect of damp soil. For example, Pettenkofer, a very prominent German hygienist, says that in two royal stables near Munich, with the same arrangements as to stalls, feed, and attendance, and the same class of horses, fever affected the horses very unequally. In one stable, fever was continually prevalent; in the other, no fever was found. Horses sent from the unhealthful to the healthful stables did not communicate the disease. The difference between the two places, says Pettenkofer, was that in the healthful stables the ground water was five to six feet below the surface, while in the unhealthful ones it was only two and a half feet from the surface. A system of drainage by which the ground water was brought to the same level under both stables made them equally healthful. The writer cannot help but feel that some other factor was involved, and while he has no doubt that excessive dampness in stables or cellars is undesirable, he does not believe that such dampness can be directly the cause of fevers of any sort. It is not desirable, however, to live over a wet cellar nor to maintain a house in a constant condition of dampness, partly on account of its bad effect on the house and partly because such dampness may, by reducing the vitality of the household, become a predisposing factor in disease. _Drainage._ From whatever source dampness may come, it can be guarded against by giving to the surface of the ground in the vicinity of the house, on all sides, sufficient slope away from the walls so that there will be no tendency for water to accumulate against the cellar walls. On the top of a hill this is very easy to do, and the natural surface grade takes care of the surface water without difficulty. On a sidehill or in a valley artificial grading has to be resorted to, except on one side. [Illustration: FIG. 3.--A grading that turns water away from the house.]