Letters 187 



tongue. But for various reasons, and led by several 

 experiments, I could never be brought to believe that 

 that milky fluid was chyle conducted hither from the 

 intestines, and distributed to all parts of the body for 

 their nourishment ; but that it was rather met with 

 occasionally and by accident, and proceeded from too 

 ample a supply of nourishment and a peculiar vigour of 

 concoction ; in virtue of the same law of nature, in 

 short, as that by which fat, marrow, semen, hair, &c., 

 are produced ; even as in the due digestion of ulcers 

 pus is formed, which the nearer it approaches to the 

 consistency of milk, viz. as it is whiter, smoother, and 

 more homogeneous, is held more laudable, so that 

 some of the ancients thought pus and milk were of the 

 same nature, or nearly allied. Wherefore, although 

 there can be no question of the existence of the vessels 

 themselves, still I can by no means agree with Aselli in 

 considering them as chyliferous vessels, and this especi- 

 ally for the reasons about to be given, which lead me to 

 a different conclusion. For the fluid contained in the 

 lacteal veins appears to me to be pure milk, such as is 

 found in the lacteal veins [the milk ducts] of the 

 mammae. Now it does not seem to me very probable 

 (any more than it does to Auzotius in his letter to 

 Pecquet) that the milk is chyle, and thus that the 

 whole body is nourished by means of milk. The 

 reasons which lead to a contrary conclusion, viz. that 

 it is chyle, are not of such force as to compel my 

 assent. I should first desire to have it demonstrated to 

 me by the clearest reasonings, and the guarantee of 

 experiments, that the fluid contained in these vessels 

 was chyle, which, brought hither from the intestines, 

 supplies nourishment to the whole body. For unless 

 we are agreed upon the first point, any ulterior, any 

 more operose, discussion of their nature, is in vain. 

 But how can these vessels serve as conduits for the 

 whole of the chyle, or the nourishment of the body, 

 when we see that they are different in different animals ? 



