24 ABSORPTION. 



glands,* the moderns have more frequently experiments referred to consisted in passing 



adopted the hypothesis of their vascular texture, injections from the veins to the absorbents, or 



so tnat we may consider this doctrine as sup- the reverse, thus proving, as was supposed, 



ported by the most recent and elaborate re- that a direct connexion subsisted between these 



searches.f See LYMPHATIC; GLAND. vessels. They were performed by the most 



2. The question of venous absorption con- skilful anatomists of the age, and were gene- 



sidered. We have now been describing those rally acquiesced in, without either the accuracy 



organs, which are more specifically or appro- with which they were conducted, or that of the 



priately termed the absorbent system, as being conclusions deduced from them, being ever 



those parts the office of which is confined to called in question. Another class of experi- 



this operation. But a very important and in- ments consisted in passing ligatures round the 



teresting question must now be discussed, thoracic duct, so as to render it impervious to 



whether the function of absorption is exclusive- the passage of the chyle, when it was supposed 



ly performed by the lacteals and the lymphatics, that under these circumstances the nutrition of 



The ancient anatomists and physiologists the animal was not interrupted,* and the same 



being unacquainted with the existence of the conclusion appeared to be substantiated by 



lacteals and the lymphatics, yet observing the various cases of natural obstruction of the duct, 



evident effect of the operation of absorption, or by certain malformations of the part, where 



ascribed these effects to the action of the veins; it was either defective, or did not convey its 



and among the moderns, for some time after the contents, in the ordinary manner, into the 



discovery of what were more appropriately veins. The other set of arguments, which are 



termed the absorbent vessels, it was still sup- more purely anatomical, were derived from the 



posed that the veins co-operated with them, supposed fact that various parts of the body, 



and in some cases were even the principal which were evidently subject to the operation 



agents. This was the universal doctrine until of absorption, were without lymphatics, and 



the middle of the last century, and was one that this was likewise the case with large classes 



of the points which was decidedly maintained of animals, the general structure of which, as 



by Haller and his disciples.^ far as regards their growth and nutrition, was 



The arguments by which the hypothesis of analogous to that of the mammalia. Admitting 



venous absorption was supported may be re- these data, it seemed to be a necessary conse- 



duced to two classes, partly of a physiological quence that absorption must in these instances 



arid pathological, and partly of an anatomical be performed by the veins, and hence it was 



nature; the first consisting of the results of inferred that in all classes of animals, and in all 



experiments performed for the express purpose parts of the body, the veins co-operated with 



of investigating the subject, and of considera- the lacteals and the lymphatics in the function 



tions derived from the morbid conditions of of absorption. 



the system; the second depending more exclu- The doctrine of venous absorption was first 



sively upon anatomical considerations. The formally called in question, nearly at the same 



time,f by Wm. Hunter and by Monro se- 



neck, but that they are not found connected with the cundus,J who, as it would appear, to a certain 

 absorbents of the abdomen, and that they are en- extent entered upon the investigation inde- 

 tirely wanting in fish and in the amphibia: Phil. , c , A ,, m c j- 

 Trans, for 1768, p. 217 et seq., and Enquiries, pendently of each other. The priority of dis- 

 pt. ii. ch. 4, 5, 6. We have the same statement covery in this, as in so many points connected 

 made by Monro. with respect to fish, p. 31. An- with anatomy, was for a long time the subject 

 tommarchi, on the contrary, asserts that birds, fish, o f warm controversy. We may remark con- 

 reptiles and amphibia have ' pochissime gl*n- cernj this question that if the judgment of 

 dule Prod, delle grande anat. di Mascagm, p. 8; ,1 i j 



but the statement is made in a general way, and e P 1686 ^ age should incline to ascribe to 



without reference to any particular observations. Hunter the Original conception of the hypo- 



It would appear that no specific apparatus for ab- thesis, it is also disposed to allow to Monro the 



sorption has been discovered in any of the inverte- me rit of establishing his opinion by a skilful and 



br * te iTr animals ' laborious process of experiment and observation. 



We have the authority of Nuck, in favour of rpi , . , l . .,, , . 



the cellular structure, Adenologia, c. ii. p. 30 et , The method which these illustrious rivals 



seq., fig. 9 . . 12 ; also of Cruikshank, c. 14 ; and of adopted was, first, to repeat the experiments 



Abemethy, Phil. Trans, for 1776, p. 27 et seq. of their predecessors, when, by noticing with 



t See Hewson, v. iii. c. 2. pi. 2; Werner and scrupulous accuracy all the circumstances con- 

 Feller, Vas. Lact. and Lymph. Descript. tab. 2; necte d with them, they were able to demon- 

 their figures, however, appear to be exaggerated ; , , J -, .. , , , 

 Beclard, add. a Bichat, p. 231 ; Monro ten?, Elem! strate > or at least to render ll hl S hl y probable, 

 v. i. p. 558. On the lymphatic glands generally that in all those cases where injections had 

 see Haller, El. Phys. ii. 3. 16. .27; Boyer, Anat. passed between the absorbents and the veins, 

 t. iii. p. 243 . . 257 -, Mascagni, ps. i. sect. 5. p. 31 ; either rupture or extravasation had taken place, 

 Rullier, ubi supra, p ) et seq ; Breschet ubi and that when thig wag carefully guar ded 

 supra, p. 394. For plates of the glands, see Mas- * 

 cagni, tab. 1. fig. 8 .. .12, tab. 2. fig. 4 . , 8, tab. 4. 



fig. 2. tab. 8, 16, 26; Cruikshank, pi. 3; Sheldon, * Some experiments of this kind are referred to 



tab. 3, 5. by M. Majendie, as having been performed by M. 



Boerhaave, Praelect. $ 103. and 247 ; Haller, Dupuytren, Physiol. t. ii. p. 167. See also Ri- 

 5n note 1. ad 106, Boerhaave, Praelect., and not. 1. cherand, Elcmens de Physiologic par Berard. 

 ad 245 ; also El. Phys. ii. 1. 28 ; Monro secun- t Medical Comment., passim ; Cruikshank, In- 

 dus, De Ven. Lymph., p. 14 .. 21 ; Walter, sur la trod.; Walter, 10 et seq. 



Resorption, Nouv. Mem. Berlin, pour 1786. .7, 15 t Dissert, de Sem. et Test, in Smellie, Thes. 



et seq.; Magendie, Physiol. t. ii. p. 238. t. ii. and De Ven. Lymph. Valv. 



