ABSORPTION BY THE SKIN. 439 



tion of the skin is, perhaps, even more considerable in the 

 higher animals than appears to be the case from the ex- 

 periments of Regnault and Eeiset just alluded to, is made 

 probable by the fact observed by Magendie and others, 

 that if the skin of animals is covered with an impermeable 

 varnish or the body enclosed, all but the head, in a 

 caoutchouc dress, animals soon die, as if asphyxiated ; 

 their heart and lungs being gorged with blood, and their 

 temperatures, during life, gradually falling many degrees, 

 and sometimes as much as 36 F. below the ordinary 

 standard (Magendie). Some recent experiments of Lashke- 

 witzch appear, indeed, to confirm the opinion of Valentin, 

 that loss of temperature is the immediate cause of death 

 in these cases, although it is not easy to understand the 

 cause of the loss of temperature. A varnished animal 

 is said to have suffered no harm when surrounded by 

 cotton wadding, but it died when the wadding was 

 removed. 



Absorption by the skin has been already mentioned, as an 

 instance in which that process is most actively accom- 

 plished. Metallic preparations rubbed into the skin have 

 the same action as when given internally, only in a less 

 degree. Mercury applied in this manner exerts its specific 

 influence upon syphilis, and excites salivation ; potassio- 

 tartrate of antimony may excite vomiting, or an eruption 

 extending over the whole body ; and arsenic may produce 

 poisonous effects. Vegetable matters, also, if soluble, or 

 already in solution, give rise to their peculiar effects, as 

 cathartics, narcotics, and the like, when rubbed into the 

 skin. The effect of rubbing is probably to convey the 

 particles of the matter into the orifices of the glands 

 whence they are more readily absorbed than they would 

 be through the epidermis. When simply left in contact 

 with the skin, substances, unless in a fluid state, are 

 seldom absorbed. 



It has long been a contested question whether the skin 



