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their powers of contraction are, during life, to a -certain degree, over- 

 come by the distending force of the fluids they convey; hence the 

 separation and absorption of chyle proceed under, their greatest possi- 

 ble area. And as there are tinu:s and cases of inanition, in which ab- 

 sorption does not proceed at all, or but dubiously, so at these times the 

 vessels being left to the operation of their tonic contractile power, will 

 be reduced to a less diameter Jhan after death. Yet will the process 

 of lacteal absorption be resumed, when the material (as in those nearly 

 starved^ is again furnished, although their area be reduced to a size 

 less than that to which they would be brought by their elastic power, 

 the only one which operates after death. Hence, if lacteal absorption 

 proceed under the extremes and intermediate degrees of area of 

 which these tubes are capable, and after death does not proceed under 

 a degree which during life was shewn to be compatible with the pro- 

 cess, the want of absorption in the former case, and the occurence of 

 it in the latter, must be attributable to something more than a de- 

 pendence upon the caliber of the vessels. This reasoning in part 

 proceeds upon the assumption of an analogy between the contrac- 

 tilities of the mesenteric absorbents and those of the arteries. 



9. The question would be in a great measure decided by the 

 result of such an investigation. But presuming upon the analogies 

 before mentioned, that the absorption of fluids by the lacteals is a 

 process in great measure, if not wholly, functional, the laws of the 

 function are to be investigated principally with a view to the settle- 

 ment of the following points: 



1st, By what is the function of the lacteal orifices constituted? 

 This question must be answered (if the function is one belonging 

 necessarily to a living structure) by properties of life, with the con- 

 currence of a structure of certain mechanical arrangement, and made 

 up of chymical constituents. 



2nd, What are the properties of life engaged in this function? 

 We cannot define them: we may say that they are peculiar, or in- 

 volve, or are connected with the common ones, viz. with those which 

 prevent decomposition of the textures; but how they are connected 

 with these we are not yet to consider. 



3rd, What share in the function is to be attributed to the vital 

 properties, and what to the mechanical and chymical constitution? 

 This is an inquiry into dependences on which a short sketch must 

 suffice. If the absorption does not take place without life, then it 

 is dependent upon life; but there is no example of a process of any 

 kind which is confessedly dependent upon life, taking place without 

 also the aid of the textures. Here, in perhaps most other instances, 

 analysis must stop; but in this we may proceed a little further: as 

 observed in the article " Relations of Vital, Chymical, and Mechani- 

 cal Properties," mechanical construction is directly related only with 

 mechanical phenomena. The spiritual and chymical agencies have 

 been said to be directly related with each other, and to be inter- 

 mixed. We are under the necessity of supposing this, because we 

 remark the perpetual changes which are mutually operated in these 



