Yet no prospective mother can afford to forget that first of all her clothing must keep the body warm. Our clothing confines a cushion of air which prevents the escape of the heat that we generate. Now, since dry air conducts heat poorly and moist air conducts it readily, the underclothes should be made of material that absorbs the perspiration; otherwise the heat that the body generates is quickly lost. Woolen garments effectually absorb the perspiration and should be given the preference. Most persons who cannot wear wool next the skin must choose cotton, since silk and linen are much more expensive; there is not in this, however, a serious deprivation. Cotton undergarments are perfectly hygienic; adapting their weight to the season of the year, one will find them equally satisfactory in summer and winter. Except in summer every inch of the body should be covered with the underclothing; this means that high-neck and long-sleeve shirts and long drawers should be worn, for healthful activity of the skin can thus be best preserved. It is well known to physicians who practice obstetrics that the kidneys fail in their work more frequently during the winter than the summer. To my mind, this is chiefly explained by the way women dress. Even with light clothing the sweat glands respond actively to the heat of summer and thus relieve the kidneys, but in cold weather the sweat glands will not remove their share of the waste products unless the clothing is warm. Nature generally indicates that the body should be kept warm during pregnancy. Many prospective mothers complain of perspiring freely; others, if reproached because they are not clad warmly enough, reply that they must wear light clothing to keep from perspiring. Thus they discount or render absolutely ineffective a most important natural safeguard against serious complications. It cannot be too strongly emphasized that warm clothing helps to maintain healthful activity of the kidneys quite as much as a proper amount of exercise and the drinking of a suitable quantity of water. The texture of the outer garments should take into account this same quality of warmth; in other respects in selecting them personal taste is an excellent guide. Outfitters carry a variety of maternity garments; patterns for such garments are also sold by dealers, so that those who cannot afford the ready-made clothes will find it easy to have them made at home. Alterations in the clothing are compulsory as pregnancy advances, and should be timely, made in anticipation of inevitable development rather than in response to it. No prospective mother need go to the extreme of "Reform Clothes"; her apparel should illustrate both her good sense and her personal pride.