LYMPHATIC SYSTEM. 193 



It has long been observed by physiologists that absorption 

 takes place only in living animals, and not in the dead ; for if an 

 intestine in a dead animal be filled with milk, none of that 

 milk will get into the lacteals ; but in the living animal, the 

 milk will readily be absorbed. This I think may be explained 

 from what is above observed of the orifices of the lacteals ap- 

 pearing to open when the villi are erected, something like 

 which may take place in the living animal ; that is, whenever 

 absorption is to be performed the blood-vessels of the villi may 

 become turgid, and the orifices of the lacteals may then stand 

 rigidly open, and be capable of attracting, like capillary tubes 

 made of hard substances. But in the dead body the villi being 

 emptied of blood, the coats of the lacteals being soft collapse, 

 by which means their orifices are closed, and they are thence 

 made incapable of attracting the chyle, or of absorbing. 



It is observable that those parts of the skin which are in- 

 tended to have more sensibility than the rest, have those pro- 

 cesses called villi most remarkably ; this is evident, when after 

 a minute injection we compare the tips of the fingers, the lips, 

 the glans penis, with other parts of the skin ; and this is still 

 more observable in the tongue, whose papillae are the instru- 

 ments of taste. In these instances some physiologists have 

 suspected that the blood-vessels were some way subservient to 

 the nerves for sensation, an opinion which I think is very pro- 

 bable ; and the use of the villi of the skin, agreeably to their 

 opinions, seems to be as organizations of vessels to become 

 more turgid at particular times, by which turgescency the ex- 

 tremities of the nerves are made more capable of doing their 

 functions; and agreeably to this idea it is observable that when 

 we attempt to taste anything extremely grateful, the papillae 

 of the tongue can be seen to become erected. 1 



And as those villi of the skin seem to be organizations 



1 The papillae of the tongue in the human subject appear to the naked eye, when 

 they are not minutely injected, quite smooth, but on a minute injection each of these 

 papillae appears covered with small vascular processes or villi ; so that in such a 

 tongue every one of the papillae seems in the microscope like a bunch of fibres, or 

 rather like a sheaf of corn ; some preparations of which, adapted to the microscope, 

 I have now by me. The learned Albinus seems not only to have observed this, but 

 to have had the same idea of the use of these processes, which he calls tubercles, and 

 has painted them like those little eminences that appear upon a nipple, but I find 

 them much longer. See his Annot. Acad. lib. i, cap. xv. 



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