ELABORATION OF NUTRIENT MATERIALS. SANGUIFICATION. 449 



close resemblance between the contents of the Lymphatics, and diluted Liquor 

 Sanguinis, seems to indicate that the former are partly derived from the fluid 

 portion of the blood, which has transuded through the walls of the capillary 

 vessels ; and we shall presently see reason to believe, that this transudation is 

 partly for the purpose of subjecting the crude materials, which may have been 

 taken up direct into the bloodvessels, to an elaborating or preparatory agency, 

 such as it seems to be the especial object of the Lacteal system to exert upon 

 the nutritive substances which it serves to introduce into the circulation. But 

 it seems not impossible that there may be another source for the contents of the 

 Lymphatics. We have already had to allude, on several occasions, to the dis- 

 integration which is continually taking place within the living body; whether as 

 a result of the limited duration of the life of its component parts, or as a con- 

 sequence of the decomposing action of Oxygen. Now the death of the tissues 

 by no means involves their immediate and complete destruction; and there seems 

 no more reason, why an animal should not derive support from its own dead 

 part, than from the dead body of another individual. Whilst, therefore, the 

 matter, which has undergone too complete a disintegration to be again employed 

 as nutrient material, is carried off by the excreting processes, that portion which 

 is capable of being again assimilated, may be taken up by the Lymphatic system. 

 If this be the case, we may say, with Dr. Prout, that "a sort of digestion is 

 carried on in all parts of the body/ 7 It may be stated, then, as a general pro- 

 position, that the function of the Absorbent System is to take up, and to convey 

 into the Circulating apparatus, such substances as are capable of appropriation 

 to the nutritive process; whether these substances be directly furnished by the 

 external world, or be derived from the disintegration of the organism itself. 

 We have seen that, in the Lacteals, the selecting power is such, that these 

 vessels are not disposed to convey into the system any substances but such as 

 are destined for this purpose ; and that extraneous matters are absorbed in pre- 

 ference by the mesenteric Bloodvessels. The case is different, however, with 

 regard to the Lymphatics ; for there is reason to believe, that they are more 

 disposed than the veins to the absorption of other soluble matters, especially 

 when these are brought into relation with the Skin, through which the lymphatic 

 vessels are very profusely distributed. 



3. Of the Elaboration of the Nutrient Materials. Sanguification. 



472. The alimentary substances, taken up by the Bloodvessels and Absorb- 

 ents, seem very far from being capable of immediate application to the nutrition 

 of the body ; for we find that they are not conveyed by any means directly into 



atics is to remove, by interstitial absorption, the effete matter, which is destined to be 

 carried out of the system ; and any undue activity in this process (such as exists in ulcer- 

 ation), and any deficiency in its energy (such as gives rise to dropsical effusions, and other 

 collections of the same kind), have been attributed to excess or diminution in the normal 

 operation of the Absorbent system. All that we at present know, however, of the process 

 of Nutrition, tends to the belief that the effete matters are carried off by the Venous sys- 

 tem; for not only do we find no trace in the Lymph of any of those substances which are 

 destined for elimination as excrementitious, but the Lymphatic vessels are either absent 

 altogether, or exist in but very small numbers, in the Nervo-Muscular apparatus, which 

 undergoes more constant interstitial change, and produces more effete matter by its disin- 

 tegration, than does any other part of the organism. It may be safely affirmed that there 

 is not a single fact to support what is known as the Hunterian doctrine ; which could never 

 have gained currency but for the authority of its great teacher its originator, perhaps, 

 having been rather Hewson than Hunter. In the first edition of this work, the Author 

 advanced the views stated above in the belief that they were original: he has since learned, 

 however, that a similar doctrine had been put forth by Dr. Moultrie, of South Carolina, in 

 the "Amer. Journ. of Med. Sci.," 1827; and by Dr. Dunglison in the first Edition of his 

 "Human Physiolosry," 1832. 



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