At first the couveuse was used only for premature and congenitally feeble infants, but its success with these soon caused the indications to be extended, until the instrument was abused it is being employed for nearly all the ills of early infancy. Then the error was recognized. And recently Delestre has stated that the couveuse should only be used for infants with subnormal temperature, and that as soon as the child has a temperature that remains at 98.6° F. it should be put in its cradle. This, to my mind, is also an error. The incubator has more extensive use than this; that is, the incubator herein described. For the Auvard incubators built on that plan, the statement may hold, for these incubators are little more than warm boxes and do nothing but heat the baby.

The first and most important indication is prematurity. We must consider as premature, infants born sooner than three weeks before term, those that weigh less than five and a half pounds and are shorter than forty six cm. The signs of prematurity need not be discussed here, save to say that children may be born near term and still be small, and children of a shorter period of pregnancy may be larger and heavier. Also, a child may weigh four and a half pounds and present stronger evidence of prematurity than one of three and a half pounds, if the latter has been longer in the uterus. All children that weigh less than five pounds, or are born with the evidences of prematurity, should be put at once in the incubator. They may not need to stay there more than two to five days, but the first hours are especially dangerous, and they need the protection the apparatus affords. Children weighing as little as two pounds and four ounces have been saved by the incubator; the smallest we saved weighed two pounds and twelve ounces. Induced labors especially indicate the incubator, because in addition to prematurity there is the shock of the interference. As a matter of fact, such children do not do as well as those where labor comes on spontaneously. Second, congenital feebleness. Infants of fair size are sometimes born weak and with poor resistance, shown by subnormal temperature, slight cyanosis, tendency to edema or sclerema. They should be treated as premature. With acquired feebleness from wasting disease, the author has had no incubator experience. The instrument, as at present perfected, I believe deserves trial here. Third, edema. Premature infants are not seldom subject to a general edema, beginning at the feet. It may be unattended with cyanosis or with urinary changes. Its cause is unknown. The incubator is the quickest way to relieve the condition. Fourth, cyanosis, with or without edema, due to feeble circulation, is very common with small infants, and sometimes present with those at full term. The warm, moistened, oxygenated air of the couveuse does wonders in these cases. Fifth, subnormal temperature, from any cause. Sixth, after difficult operative deliveries, the baby is often in a condition of shock, which, to my mind, is as common as asphyxia. Violent efforts to revive it should be limited to a minimum, and the infant placed as soon as possible in the incubator. It need stay here but one to four days. This is true of full term children, but especially true of premature. Seventh, hemorrhagic diathesis. Melena neonatorum is an indication for the incubator; likewise all congenital hemorrhagic manifestations like hemophilia, multiple hemorrhages, morbus maculosus Werlhofii. The writer has had two cases where the effect was marked, one of melena with eight profuse hemorrhages and one with hemorrhages from the nose, mouth, into the skin and with a spleen that came to the pelvis. Both recovered. Eighth, sclerema neonatorum. There are two kinds, one an edema with cyanosis and subnormal temperature, common in premature infants, a second with hardening of the fat, perhaps later with some edema, likewise with subnormal temperature, usually due to wasting diseases and the last stages of the same. For the first condition the incubator achieves brilliant results; for the latter it is useful, but not so much may be expected. The incubator has been used for the treatment of collapse from any cause, secondary, asphyxia or atelectasis, respiratory affections, as an adjunct in the treatment of syphilis, for chronic enteritis and in the arthrepsia of wasting diseases. The effects in many cases have been favorable, and further trial is indicated. On one point the greatest stress is to be laid. The premature or debile infant must be placed in the incubator at the earliest possible moment after birth. Every minute’s exposure to outside influences lessens the chances of life. To minimize the danger of exposure during the travel to the hospital, the Chicago Lying-In Hospital has an ambulance incubator constructed on the principles of Auvard’s.