CUTANEOUS ABSORPTION. 51 



till the sweat begins to flow, after which they rapidly 

 subside ; and why the remedies which, given in the 

 hot stage, added to the excitement and distress, may 

 now be productive of the best effects. 



The function next to be noticed, viz. Absorption, is, 

 in some measure, the opposite of the last. By its 

 instrumentality, substances placed in contact with 

 the skin are taken up and carried into the general cir- 

 culation, either to be appropriated to some new pur- 

 pose, or to be subsequently thrown out of the body. 



In the vaccination of children to protect them 

 from small-pox, we have a familiar example of the 

 process of absorption. A small quantity of cow- 

 pox matter is inserted under the cuticle on the sur- 

 face of the true skin, and there left. In a short 

 time it is acted upon, and taken into the system, by 

 the absorbent vessels. In like manner, mercurial 

 preparations rubbed on the skin for the cure of liver 

 complaint are absorbed, and affect the constitution 

 precisely as when received into the stomach. Many 

 even of the common laxatives, such as rhubarb and 

 croton oil, have of late been successfully adminis 

 tered in the same way, and the rapid absorption of 

 poisons from bites of rabid animals and wounds in 

 dissection through the same channel, is familiar to 

 every one. It is from the active principle of the 

 Spanish flies used in blisters being taken up by the 

 cutaneous absorbents, that irritation of the kidneys 

 and urinary organs so often attends the employment 

 of that remedy. 



The process of absorption is carried on by vessels 

 fitted for the purpose, which are thence named 

 absorbent vessels, or simply absorbents. In the skin 

 they are so exceedingly small and numerous, that 

 when injected with mercury the surface is said by 

 Dr. Gordon to resemble a sheet of silver. In health 

 they are of too small a size to admit the red parti- 

 cles of the blood, and fyence, from their contents 



