127 



ly meet him, and he never fails, by inarticulate sounds and signs of satis- 

 faction, to express to me his gratitude. 



The processof absorption is very active in children, in women, during 

 sleep, in the morning, when the body is refreshed by the night's rest. Is 

 a state of weakness favourable or unfavourable to that process ? it is well 

 known, that there are robust men who have intercourse with women in- 

 fected with the venereal virus, and who escape the contagion, unless they 

 expose themselves to it, when debilitated by excesses. A mind free of 

 fear and anxiety, has ever been considered in the Eastern countries, a 

 safe-guard against the plague. A dog, caeteris paribus, is in much less 

 danger from the bite of a viper, when suddenly bitten, than when he has 

 been sometimes gazing at the reptile, and, more or less terrified by the 

 sight. But in all these cases, does debility favour the introduction of the 

 contagious matter, by increasing theforce of absorption; or is it not more 

 probable, that by affecting the nervous system, it renders it more suscep- 

 tible of deleterious impressions* ? 



XLIL Absorption is much less active, on the external surface of the 

 body, than on the surface of its internal cavities, and in the very substance 

 of our organs. Cutaneous absorption, under certain circumstances, has 

 even so little activity, as to have led some physiologists to doubt its exist- 

 ence. The absorbing orifices of vessels which arise on the surface of 

 the body, are covered by the epidermis. This covering, which is insen- 

 sible, and, as it were, inorganic, forms a sort of separation between the 

 external and internal part of our being, and opposes, or renders more dif- 

 ficult, the absorption of substances in immediate contact with our body, 

 and if it be considered, that we are frequently immersed in the midst of 

 gases and other substances, to a certain degree, deleterious, it will be un- 

 derstood, hov/ essential it was, that the absorbing surface of the skin, 

 should not be entirely exposed, and that cutaneous absorption should not 

 be easily carried on. 



The increased weight of the body, after exercise in wet weather; the 

 abundant secretion of urine, after remaining long in the bath; the mani- 

 fest enlargement of the glands of the groin, after keeping the feet im- 

 mersed for a considerable time^in water, an experiment often performed 

 by Mascagni on himself t; the effects pf mercurial frictions, Sec. show, 



* The latter is undoubtedly the explanation. 



f It is now more than twenty years since the subject of cuticular absorption first en- 

 gaged the attention of the medical men of Philadelphia, during 1 which time, it has been 

 prosecuted with an ardour and success hig-hly honourable to those concerned- in the in- 

 quiry. As early as the year 1800, it was shown, or at least rendered highly probable 

 by Dr. Rousseau, that the pulmonary organs, and not the skin, constitute the avenue 

 through which certain substances enter the system. By cutting; oft' all communication 

 with the lungs, which he easily effected by breathing through a tube protruded into the 

 external atmosphere, lie ibund that though the surface of his body were bathed with 

 the juice of garlic or the spirits of turpentine, none of the qualities of these fluids could 

 be detected, either in the urine, or serum of the blood. Conducted nearly on the same 

 principle, but with a greater diversity of substances, experiments exceedingly well de- 

 vised and ably executed, have since been made, by persons of opposite prepossessions, 

 to an almost incredible extent. Contradictory as many of these are, a candid examina- 

 tion of the whole will still lead to a pretty satisfactory conviction, that absorption from 

 the surface of the human body does not exist as a natural and ordinary function. 



Borne down by the weight of evidence against them, most of the" advocates of the 

 ancient hypothesis were indeed prepared to abandon it, as no longer tenable, when 

 about two years no an experiment made by Dr. Massy, again revived their faith in cuti- 

 cular absorption. This experimentalist very clearly proved that if the body be immer?- 



