These infants have a poor heat production, and the natural warmth of the body must be preserved. This is best done by incubators, which supply air and moisture in stable and appropriate amounts. Chilling of the child for even a few moments may be fatal. A room may be fitted up to produce the necessary conditions of light, air, heat and moisture. The child, wrapped in sheets of cotton, except the face, is then covered with a blanket, and surrounded by a temperature varying from 88° to 95° F., which is gradually lowered to 80° F. as the child gains strength. An occasional whiff of oxygen, as prescribed for an atelectatic child, is sometimes advantageous. _Bathing._—Premature infants must not be bathed, but the skin should be cleansed with cotton and warm sweet oil or albolene. All unnecessary handling is to be avoided. _Food._—Breast milk is the secret of success with these cases. Since most of the infants are too weak to take the nipple, the breasts must be pumped, and the child fed with spoon or pipette. The interval between the feedings depends a little on the amount taken, but it should not be less than one and one-half hours, nor more than two hours. As the child gains, the interval may be lengthened to three hours. Lack of sufficient nourishment is shown by cyanosis and loss of weight, and overfeeding, by vomiting and diarrhœa. The child must be fed by hand until strong enough to nurse the breast. In certain cases of prematurity, as well as in diseases like pneumonia, scarlet fever, and diphtheria, the child must be fed by gavage. Nutritive inunctions of benzoated lard or cod-liver oil are also valuable, not only for the passive exercise supplied, but for the absorption of a certain amount of the unguent. =Marasmus= means wasting, but the term is applied to infants that steadily lose weight. The bodies of infants are so largely composed of fluid, that loss of weight occurs quite easily and rapidly. Loss of weight may be sudden or gradual. It comes on rapidly after acute diarrhœa, either with or without vomiting, or it may follow persistent vomiting without diarrhœa. Malnutrition from defective feeding is the most common cause of wasting in infants. This may be from lack of sufficient food or lack of proper ingredients, as well as irregularity of intervals, and disease. Rickets, congenital stenosis of the pylorus, congenital syphilis, and tuberculosis are all possible factors in the etiology. In any case, no treatment can be instituted until these conditions have been confirmed or excluded. =Pyloric stenosis= (the account follows Grulee) may be a thickening of the muscular coat of the outlet of the stomach (pylorus) or a spasmodic contraction. The condition is most frequent in males and in the first born.