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with related properties, and, conjoined with them, mediately-re- 

 lated substances, belonging to intestinal chyle? As the properties 

 referred to are of the spiritual kind, analysis cannot reply to this 

 question; which must therefore remain a question, on which perhaps 

 a few words might be said when we speak of secretion and absorp- 

 tion in general. 



6th, Do any changes happen to the lacteal fluid, in the course of 

 its transmission from the lacteal orifices to the left subclavian vein? 

 Do any changes occur in consequence of a function possessed, by the 

 tubes themselves, or by their glands? There is, I believe, no proof 

 of such changes. The sensible appearance of the fluid is throughout 

 pretty nearly the same. With respect to a supposed function be- 

 longing to the mesenteric glands, some remarks might be cited from 

 our pathological experience; these however will have but little 

 weight. It may be said, that if these glands are obstructed, nutri- 

 tion will be impeded : this proves only that a mechanical fitness of 

 the structure, a pervious state of the vessels, is necessary for the 

 transmission of their contents. It will be said, too, that in old age 

 the glands of the mesentery are almost entirely removed : old age is 

 sometimes attended with a diminution, and sometimes with an 

 increase of bulk.* These facts, therefore, so far as they may be 

 allowed to favour any conclusion, seem to indicate that the tubes 

 and glands of the lacteal system have no function or use, in addition 

 to that which they possess as a mechanical structure. This opinion 

 derives its principal credit from the circumstance that whatever 

 variety the tubes and glands of the mesentery might suffer from 

 disease, the variety affects only the quantity of fluid transmitted to 

 the sanguiferous system, while the quality and appearance of the 

 fluid have not been observed to suffer any alteration which might 

 be imputed to a disordered function. If I were inclined to con- 

 jecture upon the use of absorbent glands, as one might conjecture, 

 in infinitum, upon things where the evidence is of the most dubious 

 and insignificant kind, I say if I were disposed to do this, I could 

 add but very few conjectures to those worthless ones which have 

 been already proposed upon this subject which is as well left alone. 



7th, As it may be said to have been shewn that the separation 

 and absorption of lacteal fluid is probably accomplished by the 

 spiritual properties of the structure, or by its life; the nature of this 

 life, or the history of these properties, is next to be inquired after: 

 here there is little to be done but to recur to a leading division 

 which has been proposed with respect to the other organs. It is to 

 be inquired, is the assimilating, also the functional life of the lacteals? 

 or, is the latter of the regular dependent, or of the occasional kind? 

 The choice lies between the two former, and the only clue for the 

 investigation is that before mentioned to have been adopted in some 



* Is such spontaneous removfcl of the glandular structure of the absor- 

 bents attended with an obliteration of the absorbent vessels, which before 

 passed through it, or is the continuity of permeable absorbent tubes pre- 

 served amidst the absorption of connected structure? 



