OP SANGUIFICATION. 275 



the viscera and other soft parts, formerly secreted from 

 the blood, and, therefore, already imbued with an ani- 

 mal nature, and easily, without doubt, again miscible 

 with the mass of blood, to which it does but return. 



449. Something is contributed by the slow and almost 

 stillatitious manner in which the chyle drops into the 

 blood through the last valve of the thoracic duct, these 

 very minute portions becoming thus the more intimately 

 combined with the blood. 



450. The heart, too, by means of the remarkable pa- 

 pillary muscles of the ventricles, agitates and mingles 

 the blood just impregnated with fresh chyle. 



451. The great importance of the lungs which receive 

 the blood immediately after its addition of fresh chyle, 

 and also of respiration, in the business of assimilation,* 

 will be evident on considering the extraordinary vas- 

 cularity of those organs (14) and their constant and 

 regular motion. 



452. The remaining part of sanguification is accom- 

 plished by the general circulation and the powers which 

 aid it, particularly by muscular motion, &c. 



453. Although so many means are provided for the 

 combination of the chyle with the blood, and although 

 the constituents of the chyle somewhat resemble those 

 of this fluid ; nevertheless, it is commonly asserted 

 that many hours are required for the complete change 

 of the colour of the chyle and for its assimilation. Be- 

 sides other arguments in favour of this assertion, the 

 pathological fact is urged, that chyle is frequently seen 



* Especially, according to the opinion of Cuvier, in the conversion of the 

 chyle into the lymphatic or fibrous part of the blood. Ldcons A' Anatomic 

 Comparee. T. i. p. 91. T. iv. p. 304. Thomson, System of Chemistry. Vol. iv. 

 p. 497. Bostock's work, recommended above, in the chapter on Respiration. 



T 2 



