32 



ABSORPTION. 



aqueous vapour diffused through the atmos- 

 phere. This supposed power of cutaneous ab- 

 sorption was called in to account for various 

 physiological or pathological facts, for which 

 it appeared to afford a plausible explanation, 

 while, on the other hand, the easy mode in 

 which it appeared to account for these facts 

 was made use of as the great argument to 

 prove its existence. The statical experiments 

 of Sanctorius, which have, since his time, 

 been so much multiplied and extended, were 

 supposed to prove unequivocally that the body 

 is capable of gaining weight independently of 

 any substance received into the stomach, and 

 to account for this addition, recourse was 

 always had to the cutaneous absorption. Of 

 late, indeed, it has been discovered, that a part 

 of the effect ascribed by Sanctorius to the 

 action of the skin is in reality due to the lungs, 

 but still, after making the necessary deduction 

 for the operation of the latter organ, there re- 

 mained a certain increase of weight, which it 

 was supposed could only be accounted for by 

 admitting the existence of the cutaneous ab- 

 sorption.* 



The doctrine of cutaneous absorption has, 

 however, been altogether called in question by 

 Seguin, who performed a series of experiments, 

 which consisted in immersing a part of the 

 body in a saline solution, for example, that of 

 corrosive sublimate, the effects of which on the 

 system at large would be easily recognized, 

 if any part had been absorbed. The result 

 was, that when the cuticle was entire, no effect 

 that could be attributed to absorption took 

 place, and the conclusion seemed not unna- 

 tural, that under ordinary circumstances it did 

 not exist, f Currie was led to form the same 

 conclusion by accurately weighing the body 

 before and after immersion in the warm bath, 

 under circumstances which were conceived to 

 be favourable to the process,! and as the re- 

 sults of his experiments coincided with those 

 of Seguin and others, the doctrine of cuta- 

 neous absorption, except under the particular 

 circumstances mentioned above, was very 

 generally abandoned. Experiments have been 

 adduced to prove, that even under these par- 

 ticular circumstances, when substances are ap- 

 plied by friction to the surface, they do not 

 enter into the mouths of the vessels, but being 

 volatilized by the heat of the body, that the 

 vapour thus produced is inhaled by the lungs ; 

 an opinion which one might be inclined to 

 think was almost too extravagant to be seri- 

 ously maintained. 



The subject of cutaneous absorption has 

 been lately investigated by Dr. Edwards, with 

 that skill and address which he has applied to 

 so many departments of physiology. By a 

 number of experiments, which were performed 

 on cold-blooded animals, where it was more 



* Mascagni, p. 22, 3; see also Kellie, in Ed. 

 Med. Journ. v. i. p. 170 et seq.j and the article 

 " Integuments " in Rees's Cyclop. 



t Fourcroy, Med. Eclair, t. iii. p. 232. . 241, and 

 Ann. Chim. t. xc. p. 185 et seq. 



$ Med. Reports, ch. xix. 



Ed. Med. Journ. v. ii. p. 10 et scq. 



easy to observe the effects, he found that ab- 

 sorption was carried on, to a considerable 

 extent, when the animal, or a part of it was 

 immersed in water. The conclusion which 

 the experiments seemed to warrant was, that 

 transudation and absorption are, at all times, 

 going forwards at the surface, but that the 

 operations proceed at different rates, according 

 to the circumstances in which the animal is 

 placed, and that the body gains or loses weight, 

 in proportion to the excess of one of them 

 above the other. The analogy of the cold- 

 blooded animals he applies to those with warm 

 blood, and he supposes that they are subject 

 to the same double action, a conclusion which 

 appears to be confirmed by some experiments 

 that were performed on guinea-pigs immersed 

 in moist air, when an increase of weight was 

 found to have taken place, which, after taking 

 every circumstance into consideration, seemed 

 necessarily to depend on absorption.* With 

 respect to the experiments of Seguin, Dr. Ed- 

 wards is not disposed to call their accuracy in 

 question, but he points out various circum- 

 stances connected with them, which he con- 

 ceives would tend to increase the transudation, 

 and to diminish, or even entirely to suspend 

 the absorption.f The experiments of Dr. Ed- 

 wards, considered in all their relations, are 

 generally conceived to decide the question 

 respecting the existence of cutaneous absorp- 

 tion, under the ordinary circumstances, and in 

 the natural conditions of the system. 



.4. Of the specific uses of the different 

 parts of the absorbent system, and of the rela- 

 tion which that system bears to the other vital 

 functions. Whatever opinion we may form on 

 the controverted question respecting venous 

 absorption, and in whatever manner we may 

 explain the action of the lacteals and the lym- 

 phatics, there can be no doubt that their spe- 

 cific use is to absorb certain substances which 

 are presented to their extremities.J There is, 

 however, so well marked a distinction between 

 the situation and the anatomical relations of 

 these two kinds of vessels, as well as between 

 the substances that are found to be contained 



* De 1'Influence des Agens, &c. ch. xii. p. 345 

 et seq. 



t De 1'Influence, &c. ch. xiii. p. 556 et seq. 

 See on this subject, Magendie/Physiol. t. ii. p. 189 . . 

 196, and Diet, de Med. et Chir. Prat. " Absorp- 

 tion ;" where he endeavours to prove, that it is the 

 veins and not the lymphatics which are the agents 

 in cutaneous absorption. See also the remarks of 

 M. Rullier, ch. ii. ; and of M. Adelon, Physiol. 

 t. iii. p. 10 et seq. ; also art. " Absorption/' 

 Diet, de Med. t. i. p. 124 et seq. M. Chaussier 

 found that sulphuretted hydrogen gas, when ap- 

 plied to the surface of the body, manifested its 

 deleterious effects on the system, Bibl. Med. t. i. 

 We have already had occasion to notice the opinion 

 of Walter on this subject, p. 25, which is similar 

 to that of M. Magendie. M. Buisson attempts to 

 establish a distinction between the absorption which 

 is carried on by the membranes and by the cellular 

 texture, De la Divis. des Physiol. Phenom. p. 251 

 et seq. 



t M. Magendie indeed doubts this position so 

 far as the lymphatics are concerned ; Journ. Phy- 

 siol. t. i. p. 18 et seq. and Physiol. t. ii. p. 238. . 



