352 ON DIGESTION AND NUTRITIVE ABSORPTION. 



of a sufficient supply of food, may live upon their own flesh ; and there seems 

 no reason why it should not be as capable of re-conversion into living tissues, 

 as is that of the animals on which they feed. A very similar phenomenon is 

 observed in Vegetables.* It may be stated, then, as a general fact, that the 

 function of the Absorbent System is to take up, and to convey into the Circu- 

 lating apparatus, such substances as are capable of appropriation to the nutri- 

 tive 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 de- 

 stined for this purpose ; and that extraneous matters are absorbed in preference 

 by the Mesenteric Veins. 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. 



469. Since the time of Hunter, who first brought prominently forwards the 

 doctrine alluded to, it has been commonly supposed that the function of the 

 Lymphatics 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 pro- 

 cess (such as exists in ulceration), or 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 Absorb- 

 ent System. From what has been stated, however, it appears that the special 

 function of the Lymphatics, like that of the Lacteals, is nutritive absorption ;t 



* See Principles of General and Comparative Physiology, 403. 



f The Author, at the time of the publication of the First Edition of this work, believed 

 this view to be altogether novel; he has since learned, however, that a similar doctrine 

 had been put forward by Dr. Moultrie, of South Carolina, in the American Journal of the 

 Medical Sciences, for the year 1827. 



[In the American Journal of the Medical Sciences, for 1827, Dr. James Moultrie pub- 

 lished an essay on the " Uses of the Lymph," in which, amongst other things, attempted 

 to be sustained, will be found the following views. 



1. The lacteals and lymphatics do not constitute, as they are supposed to do, the 

 absorbent system of the animal economy ; they do not, as the absorbent theory supposes, 

 remove from the organs the " cast off molecules" of which they are composed, or carry 

 out of the body the "effete" particles disintegrated by the act of the assimilative function. 

 The one is engaged in the preparation and introduction of chyle, and chyle only, into 

 the blood; the other in elaborating an organizable product a recrementitious secretion 

 destined to unite with it for objects of a common and nutritious nature. 2. The primary 

 object of the lymph, and that for which it is made to commingle with the chyle in the 

 thoracic duct, is the vitalization of the latter fluid. 3. The truly "effete" matter of the 

 body is the carbonaceous element of the venous blood, to which may be added the urea 

 or azotic element of the urine. Than these, we know of nothing to which that term can 

 be applied. 4. The venous and not the lacteal or lymphatic system, therefore, is the 

 " absorbent system," in any disintegratory or effete sense of the phrase. 5. Nature, in 

 effecting the elimination of excrementitious matter from the constituency of the solid or 

 fluid parts, appears to aim at restoring to the physical universe, the matter temporarily 

 borrowed for subsistence, in a state of elementary simplicity, or an approximation there- 

 to ; that is, the carbon as carbon, the azote as azote, and hydrogen and oxygen as hydro- 

 gen and oxygen. The lungs she uses as one medium of escape ; the kidneys as a second ; 

 and the skin as a third, &c. Hence, the carbonic acid gas of respiration; the urea of 

 the kidneys, and the aqueous exhalations of the skin, pulmonary transpiration and 

 urine. 



These doctrines have been regularly taught by Dr. M., in his course of lectures on 

 physiology, delivered in the Medical College of the State of South Carolina, since the 

 establishment of the College in 1833. They have also been recently enforced in a bro- 

 chure published by Dr. M., in which he asserts and vindicates his claim to their paternity. 

 On the Organic Functions of Animals. By JAMES MOULTBIE, M. D., etc., Charleston, S. C. 

 1844. M. C.] 



