THE SKIN. 371 



interchanges, and thus prevents the fruit from drying as long 

 as it is perfect ; the slight dryness which appears, is effected 

 by means of the pedicle. 



The structure of the epidermis is not, however, well 

 adapted for the penetration of fluids deposited upon its sur- 

 face, and the question arises how they can pass through these 

 corneous layers covered as they are with fatty matter. Arti- 

 ficial absorption can only be indirectly produced: for this 

 purpose, fatty substances (ointments or pomades) are em- 

 ployed, which mix readily with the fatty matter of the 

 epidermis ; if watery fluids are to be introduced, the skin is 

 carefully washed, and cleansed as thoroughly as possible, and 

 yet, in spite of this ablution, scarcely any absorption takes 

 place. That fatty bodies do not allow of the absorption of 

 medicines is due to the fact that these mingle with the oily 

 secretion of the skin; whilst the glyceroles or glycerides 

 (such as plasma, etc.), moreover, are, perhaps, even less 

 absorbable than water. That the skin has any power of 

 absorption must therefore be almost totally denied. 1 If a 

 substance is to penetrate the organism through the skin, it 

 must be placed in the deep layers of the epidermis, the layer 

 of Malpighi, and there is no need to go beyond this; for in- 

 stance, in vaccination, the substance (vaccinal lymph) need 

 only be placed in contact with those globular layers which 

 are extremely sensitive and impressible : this method is now 

 very generally employed, and is called the endermic method, 

 though it might, in some cases, be better called the enepi- 

 dermic. 



The skin is permeable by gas : Bichat's experiment is well 

 known, showing that the cutaneous surface of a limb, if im- 

 mersed in putrid gases, absorbs them ; so that, being intro- 

 duced into the organism, they finally pass out through the 

 lower part of the digestive tube. All kinds of miasma appear 

 to penetrate the organism in this way with the greatest ease. 

 The ready absorption of gas by the skin has led some authors 



1 And yet there are experiments recorded in many standard 

 works, which have been collated and criticised by Dr. Stille 

 (" Therapeutics and Mat. Med.," 4th ed., pp. Gl et M(].), accord- 

 ing to which it must certainly be admitted that certain salts in 

 aqueous solutions, as even, perhaps, water itself, can be absorbed 

 by the cuticular covering. Certain experiments undertaken by the 

 Am. editor induce him to believe that bromide of potassium can be 

 absorbed by the endermic method. (Vide " Bromides of Potas- 

 sium," by E. H. Clarke and R. Aniory. Boston, 1372.) [Am. ed.] 



