V 57 



stomach, and in tlie bowels; and here, as every 

 where else, it has been obliged to stop short, 

 where the nervous system has begun to determine 

 the chemical state of these processes. 



Through BICHAT'S excellent investigation into 

 the membranes of the body, we have acquired bet- 

 ter information relative to the vessels, in which the 

 processes of digestion are performed, and have also 

 been enabled to attain a more precise chemical 

 knowledge of the composition of the membranes 

 of vessels. The whole intestinal canal, and all 

 the reservoirs, with their excretory ducts, which 

 have any connexion with it, are coated on the 

 inside with a mucous membrane ; so called, be- 

 cause it keeps itself constantly covered with a 

 mucus, by which it is defended against any effect 

 from those bodies, with which it comes in con- 

 tact. The chemical composition of this mucous 

 membrane has been satisfactorily examined by 

 BICHAT : its principal character is insolubility 

 in boiling water we derive no glue from it like 

 that from cellular and serous membranes (M. se- 

 rosse) ; and of all parts of the body, the brain ex- 

 cepted, it is soonest destroyed by being macerated 

 in cold water, or treated with acids. The mu- 

 cus, with which the membrane is covered, is aU 



