3G0 Dr Craigie's Observations on the 



of brute animals opened alive, " for in these," lie adds, " you 

 will find the venous artery (the pulmonary) full, not of air or 

 smoky fumes, as the Aristotelians assert, but of natural blood."" 



In the same book he describes accurately the distribution of 

 the peritoneum, and is the first who recognises its twofold ar- 

 rangement. He gives a good description of the situation, figure, 

 and structure of the womb, and rectifies some mistakes of Mun- 

 dino, who had represented it as containing seven chambers or cells. 



The fourteentli book is exclusively devoted to the subject of 

 vivisection, and the facts thus to be determined. If neither ape 

 nor bear nor lion is to be got, he prefers the dog to the hog, 

 first, because the latter are less convenient for distinguishing 

 the use of the recurrent nerves ; secondly, because they are too 

 fat; and, ihirdy, because the grunting noise of the animal is ex- 

 tremely disagreeable. Columbus, therefore, had recourse to the 

 dog, in which he recognised the motion of the larynx in voice, 

 the alternate descent and ascent of the diaphragm in inspira- 

 tion and expiration, the motion of the heart and arteries, which 

 are dilated, he says, while the former contracts, and contracted 

 during the dilatation of the heart, — and the alternate heaving 

 and sinking of the brain, guod jjaucls notum est. He describes 

 with some minuteness the process for exposing the recurrent or 

 laryngeal nerves ; the division of which, he observes, is followed 

 by loss of voice. And to prove that voice depends on the la- 

 rynx and its nerves, and not on the heart, as asserted by Aris- 

 totle, after tying the large vessels, he cut out the heart of a dog, 

 and shewed that the animal still barked and walked. On these 

 animals, also, he practised artificial respiration, with the effect 

 of exciting the action of the lieart. Lastly, he recognised the 

 motion of the brain, which depends on arterial and cardiac pul- 

 sation. 



In his fifteenth book he records all the singular deviations of 

 structure with which he had met ; but these, as belonging ra- 

 ther to pathology, it is unnccessar}' to specify. 



On the whole, it may be inferred that the great merit of Co- 

 lumbus consists in demonstrating the small or pulmonary cir- 

 culation, and making a very near approach to the true doctrine 

 of respiration, by means of the experiments which he performed 

 on living animals. 



