ABSOEPTION FKOM THE EESPIKATOEY SURFACE. 455 



were exposed for a long time without water in an open boat. 

 With regard to his sufferings from thirst, he says : " I cannot 

 conclude without making mention of the great advantage I 

 derived from soaking my clothes twice a day in salt water, 



and putting them on without wringing There is 



one very remarkable circumstance, and worthy of notice, 

 which was, that we daily made the same quantity of urine as 

 if we had drunk moderately of any liquid, which must be 

 owing to a body of water absorbed through the pores of the 

 skin. ... So very great advantage did we derive from 

 this practice, that the violent drought went off, the parched 

 tongue was cured in a few minutes after bathing and washing 

 our clothes ; at the same time we found ourselves as much 

 refreshed as if we had received some actual nourishment." * 



The mechanism of the introduction of various salts in 

 solution in water and of certain medicinal substances through 

 the skin belongs chiefly to therapeutics. There can be no 

 doubt of the penetration of numerous articles simply placed 

 in contact with the surface ; and it is well known that the 

 skin denuded of its epidermis absorbs soluble substances 

 with great rapidity. Though observations on the absorption 

 of salts in medicated baths are somewhat contradictory, there 

 are enough positive experiments on this point to leave no 

 doubt as to the actual penetration of these principles, which 

 are to be recognized, indeed, in the urine. The penetration 

 of most medicinal substances by the skin is very much facili- 

 tated by frictions, employing what is known in therapeutics 

 as the iatroleptic method. 2 



Absorption from the Respiratory Surface. In studying 

 the physiological anatomy of the respiratory apparatus, we 



1 Narrative of Captain Kennedy's losing his vessel at sea, and his distresses 

 afterward, communicated to his owner. Annual Register, London, 1769, p. 190. 



2 For a full account of the absorption of medicinal substances by the healthy 

 skin, the reader is referred to the article by Delore, in the Journal de la Physiolo- 

 gie, Paris, 1863, tome vi., p. 249 et seq. 



