Department of Obstetrics (tantl Gynncology, th1e Mirthodist ]Api.SCOl Hospital')Brooklyn, Ac,, ) rk? THE initial gcasp after birtlh is normally a vigorouis ins)ira-tory effort thalt opens, the airways and some of the alveoli of the lUngs. It is the most importan1t eveent in every life, and is quite dlistinct from subsequent respirations. Once breathing, howNever irregular and shallow, has (leveloped, effective iiieans of augmenting it are available, but there is no one generally accepted measuire for initiating the first inspiration. If this does niot occur spontaneously, the life of the child depends lIponl the measures employed.The onset of respiration is believedl to be caused by clieruiical, rather than by physical factors. An explanation of this phenomenon satisfactory for our purpose is, that immediately after delivery, the placental circulatioin is markedly impaired by the contracting, retracting uterus. This results in a (liminution of the oxygen sulpply to the baby and a. marked increase of the carbon-dioxide tension in the blood which stimulates the respiratory centre to action. We are all born in a coiiditioil of a,pnea, but it is only when this state persists for an uniedulv long period of time that there is cause for alarm. In the majority of prolonged apnoeas the conistant increase in the carbon-dioxide tenisioni, plus the mieasures einployed by the obstetrician, result in an inspiratory gasp, and apprehension is relieved. More and(l mnore often this favourable outcome is niot experienced so easily sometimes, niot at all.It is in an effort to face this problem that this paper is presented.We shall deal only with severe ca,ses of respiratory depression and asphyxia. Clinically most of them correspond to w\-ha,t is known as " a.sphyxia pallida ", which term will be frequently employed. At other times w-e shall use the word stillborn, indicating in either case a, ba.by in a, state of shock, very pale, with a relaxed mnusculature and absent superficial reflexes, who ha,s not breathed, but whose circulation persists. As far as treatment is concerned there is another class of babies: those which are so deeply narcotized anid anmesthetized as to be in serious danger. AlthoughlThe investigation was aided by a granit from the Lindredge Research Fund of the Hospital.