1863.] 387 



sophical Transactions 5 for 1772. In this communication Hunter 

 notices that in occasional instances, especially in persons who have 

 died of sudden and violent deaths, the stomach is found on inspection 

 to have undergone solution, to the extent of perforation, from the 

 action of its own secretion upon it. Hunter considered that this 

 could only have taken place after death ; and to account for why the 

 same occurrence did not ensue during life, he adduced the living prin- 

 ciple as constituting the protecting agent. The fact that parts of 

 living animals, as shown hy Claude Bernard of Paris, are susceptible 

 of digestion when introduced through a fistulous opening into a 

 digesting stomach, proved that Hunter's explanation does not stand 

 the test of experiment. The author corroborated Bernard's results 

 upon frogs, and referred to an experiment in which he had also 

 obtained the digestion of the extremity of the ear of a living rabbit. 

 The view at present most generally entertained is, that the epi- 

 thelial lining or mucus protects the stomach from undergoing 

 digestion during life. This it is supposed is acted upon and dis- 

 solved, but being as constantly renewed, the stomach escapes injury. 

 There being no longer the power of producing epithelium after 

 death, accounts for the occurrence of the solution that may then be 

 observed. 



To test this view, the author removed a patch of mucous membrane 

 about the size of a crown piece from the stomach of the dog. Food 

 was afterwards digested without, however, the denuded stomach 

 showing the slightest sign of attack. It thus appearing that the 

 stomach resisted digestion notwithstanding the assumed protecting 

 layer had been removed, it became evident that something besides 

 the epithelial lining was required to account for the security enjoyed. 



Seeing that the question was still open for explanation, the fol- 

 lowing was the view propounded by the author. The existence of 

 acidity, it was first remarked, is an absolutely essential condition for 

 the accomplishment of the act of digestion. During life the walls of 

 the stomach are most freely permeated by a current of alkaline 

 blood. Under such circumstances it would appear impossible that 

 any digestive action could be effected. There would be one condition 

 that would neutralize the other. Acidity is needful for digestion, and 

 alkalinity is a constant character of the blood. As long therefore as 

 so free a circulation of this alkaline fluid should be maintained (and 



