OF RESPIRATION. 91 



respiration after birth, we shall show to be very diffe- 

 rently accomplished in the foetus, viz. by means of the 

 connection of the gravid uterus with the placenta. 

 Put when the child is born and capable of volition, the 

 congestion of blood that takes place in the aorta, from 

 the obstruction in the umbilical arteries ; the danger of 

 suffocation from the cessation of those changes of the 

 blood, in regard to oxygen and carbon, (13) hitherto 

 produced in the uterine placenta ; the novel impression 

 of that element into which the child, hitherto an aquatic 

 being, is conveyed ; the cooler temperature to which it 

 is now exposed ; and the many new stimuli which are 

 now applied, seem to induce new motions in the body, 

 especially the dilatation of the chest and the first 

 inspiration. 



The lungs being for the first time dilated by inspi- 

 ration, open a new channel to the blood, so that, 

 being obstructed in the umbilical arteries, it is derived 

 to the chest. 



Since the inspired air becomes hurtful and unplea- 

 sant to the lungs by the decomposition which it expe- 

 riences, I should ascribe to the most simple corrective 

 powers of nature, the subsequent motion by which the 

 poisonous mephitis, as it may be called, is expelled 

 and exchanged for a fresh supply. 



The consideration of all these circumstances, espe- 

 cially if the importance of respiration to circulation, 

 demonstrated by the well-knoAvn experiment of Hooke,* 



* It bears the epithet Hookian, because it was most adorned by Rob. Hooke. 

 Sec Th. Sprat, History of the Royal Society. Lond. 1<>(>7. 4 to. p. 232. But 

 it was before instituted by Vesalius, and very much praised for its beauty. 

 De c. h. Fabrica. p. 824, 



