DERM01D SYSTEM. 301 



lities, the second in paralysis. .Next, there are the diseases 

 of the cellular texture of the chorion, as the inflammation 

 of that texturfe over a bile or phlegmon. Then there are 

 diseases of the external capillary net-work, as erysipelas, 

 herpes, measles, scarlatina. The chorion, lastly, is subject 

 only to chronic affections, as elephantiasis. 



Q. What important inference is to be deduced from 

 this division of the diseases of the skin? 



#. That all those diseases, except those in which ani- 

 mal sensibility is exalted or diminished, proceed from an 

 alteration of the organic sensibility and insensible organic 

 contractility of the parts. And it is from these alterations 

 that numerous phenomena are to be accounted for, as the 

 failure of blisters to draw from too much or too little ex- 

 citement, in the greater or less sweating at different times. 



Q. Will you enumerate some remarkable passive sym- 

 pathies of the dermoid telkture? 



/#. One very striking one is the sensation of cold pro- 

 duced by disorder of the internal organs; these affect the 

 animal sensibility of the skin. Flushes of heat are also 

 from this cause. Digestion, the emission of semen, the 

 diseases of the serous and mucous systems, all produce 

 chilliness. 



Q. The sensations, then, of heat and cold, arise from 

 various causes? 



*#. Yes. They arise from an increase or diminution of 

 atmospheric temperature; from preternatural development 

 in some diseases, as of heat in phlegmon; there is a dimi- 

 nution of heat in other cases, as where an artery is tied. 

 Caloric Ss disengaged sometimes, generally or locally, 

 without inflammation; lastly, there are sympathetic sensa- 

 tions of heat and cold. 



