228 RESPIRATION. 



the cessation of those changes of the blood, in regard to oxygen and 

 carbon, hitherto produced in the uterine placenta ; the novel im- 

 pression 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 inspiration, 

 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 unpleasant to the 

 lungs by the decomposition which it experiences, 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, especially if 

 the importance of respiration to circulation, demonstrated by the 

 well-known experiment of Hooke m , be remembered, will, in my 

 opinion, explain the celebrated problem of Harvey n , better than 

 most other attempts of physiologists. P 



m " It has the epithet Hookian,*because it was most varied by Rob. Hooke. 

 See Th. Sprat, History of the Royal Society. Lond. 1667. 4to. p. 232. But 

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

 c. h. Fabrica, p. 284." 



The experiment consisted in laying the lungs completely bare, and reviving 

 the animal by artificial respiration. Hooke varied it by pricking the surface of 

 the lungs, and forcing a continued stream of air through them. 



n " Wm. Harvey, De circulat. sanguin. ad J. Riolan. p. 258. Glasgov. 1751. 

 12mo." 



These are the words of Harvey : " It would appear that the use of expir- 

 ation is to purify and ventilate the blood, by separating from it these noxious and 

 fuliginous vapours." We must not, however, forget the words of Servetus, 

 seventy years before, and already quoted at p. 195. exjriratione Juligine expur- 

 gatur. 



" And especially his Exerc. de gener. Animalium. p. 263. Lond. 1651. 4 to." 



" See Theod. C. Aug. Roose, uber das Ersticken neugeborner Kinder, in his 

 Physiologisch. Untersuchungen. Brunsw. 1796. 8vo. 



J. D. Herholdt, De vita, imprimis feetus Immani, ejusque morte sub partu. 

 Havn. 1802. 8vo." 



P Consult, for example, Petr. J. Daoustenc, De Respiratione. Lugd. 1743. 

 4to. p. 54. sqq. 



Rob. Whytt, On the Vital and other Involuntary Motions of Animals, p. 222. 

 Edinb. 1751. 8vo," 



