128 



however, in an unquestionable manner, that absorption takes place through 

 the skin, with more or less rapidity, according to circumstances. It must 

 be taken into account, that the means which promote cutaneous absorp- 

 tion, operate, at least as much, by altering the structure of the epidermis, 

 as by increasing the action of the absorbing orifices. In this manner 

 the bath appears to operate, by softening the 'texture of the epidermis : 

 and frictions, by displacing and raising its scales. 



It is by means of frictions, that we succeed in introducing into the lym- 

 phatic system, medicines possessing purgative, febrifuge, sedative, or 

 diuretic qualities, combined with the gastric juice, or diluted in any other 

 liquids, for, as has been shown by the experiments performed at the Sal- 

 petriere, by.M. M. Dumeril and Alibert, in the name of the Philomatic 

 Society, the mixture with saliva or gastric juice, of the medicines which 

 are to be administered by friction, is not necessary to insure their absorp- 

 tion. Extract of opium has soothed pain, bark has checked fits of inter- 

 mittent fever, rhubarb has procured alvine evacuations : squills have 

 stimulated powerfully the action of the urinary organs, nor has the pre- 

 vious mixture, with gastric juice, of these substances reduced into pow- 

 der, seemed to increase or diminish their efficacy. 



Absorption takes place quickly and readily, wherever the epidermis is 

 thin, habitually moist, and the skin delicate, so as to leave almost bare of 

 covering, the subjacent parts, as on the lips, in the inside of the mouth, 



ed in a decoction of madder, the colouring 1 matter of this substance will be taken in, and 

 may be displayed in the urine, by using any one of the alkalies as a test. 



Determined, if possible, to put this long 1 agitated question to rest, Dr. Rousseau, as- 

 sisted by his friend, Dr. Samuel B. Smith, has subsequently performed a series of ex- 

 periments, many of which we witnessed, with every variety of substance, mild and acrid, 

 volatile and fixed, nutritive, medicinal, and poisonous. 



The result of these extensive researches is : 



1. That of all the substances employed, madder and rhubarb are those only which 

 affect the urine The latter, of the two, the more readily enters the system. Neither 

 of these substances can be traced in any other of the secretions, or excretions, or in the 

 serum of the blood. 



2. That the power of absorption is limited to a very small portion of the surface of 

 the body. The only parts indeed which seem to possess it, are the spaces between 

 the middle of the thigh and hip, and between the middle of the arm and shoulder. To- 

 pical bathing 1 with a decoction of rhubarb or madder, or poultices of these substances 

 applied to the back, or abdomen, or sides, or shoulders, producing- no change in the 

 urine, &c. Equally ineffectual was the immersion of the feet and hands in a bath of the 

 same materials. After being 1 kept in it several hours, not the slightest absorption was 

 afforded. 



Such is the state in which this interesting- subject is at present left. Though, per- 

 haps, n<it absolutely decided, enough surely has been done to demonstrate that cuticu- 

 lar absorption rarely happens, and whenever it does, it cannot be deemed the effort of 

 a natural function. Covered, as is the whole surface of the body by the impervious 

 cuticule, it is manifest to us that absorption can only take place in one of two ways, 

 either by forcing the substance under the scales of the epidermis, as in the instance of 

 the application of frictions, or by long" continued bathing 1 , the cuticle becomes so chang- 

 ed in its organization, as to admit of transudation, or the insinuation of the fluid under 

 its squamous structure, so as to come in contact with the mouths of the lymphatics situ- 

 ated within. 



At all events, whatever difference of opinion may be entertained as to the degree of 

 conclusiveness of the experiments to which I have alluded, it can hardly be thought ne- 

 cessary to resort to cuticular absorption, to explain the facts enumerated by our author 

 as proofs of the existence of the function. These, and, perhaps, all other phenomena, 

 hitherto referred to the agency of absorption by the skin, may be more rationally ac- 

 counted for on the principle of pulmonary absorption, and the b>v of sympathy. 

 Chapman. 



