434 MUCOUS MEMBRA^"ES. 



their dysenteric fornij we saw a reason for tlic extravasation of 

 blood either into the parench3'ma of tlie mucous membrane, or 

 upon its surface. Now on the gastric and duodenal mucous 

 membrane tliere occur a series of conditions, characterised by 

 loss of substance, which may ver}' plausibly be referred to ante- 

 cedent parench}Tiiatous hasmorrhages — to hsemorrhagic infarc- 

 tions of the mucous membrane. This view is generally adopted to 

 explain HiE:\roEKHAGic erosions. Under this term we under- 

 stand certain sharply- circumscribed, circular defects of the 

 mucous surface, no larger than a pin's head, which commonly 

 occur in great numbers, their favourite seat being on the free 

 borders of the mucous folds in the pyloric region. Tlie fr*e- 

 cjuency of hgemorrhagic infiltrations of the same size and shape, 

 existing side by side with the erosions, raises the probability of 

 their originating in this way to a certainty. Moreover there 

 is usually a history of attempts at vomiting, to account for the 

 presence of the hasmorrhagic extravasations ; so that we may 

 fairly assume the sequence of phenomena to have been something 

 like this : the act of vomiting, by temporarily arresting the 

 return of blood, causes minute extravasations from the superficial 

 venous radicles of the gastric mucous membrane ; these occur on 

 the free borders of the folds, the extreme parts of the congested 

 area, where the blood- pressure must attain its maximum intensity. 

 The extravasated blood-corpuscles infiltrate a circumscribed 

 patch of the mucous membrane to such an extent as to compress 

 the capillaries, thus putting a stop to circulation and nutrition. 

 The hannorrhagic infarction becomes a caput mortuum, its 

 organic union with the healthy mucous membrane is at an end, 

 and its actual detachment becomes merely a question of time. 

 When we reflect] how easily the gastric juice can dissolve such 

 dead parts as these hemorrhagic infarctions, we shall readily 

 understand how it comes about that a very few hours after the 

 bleeding has occurred, we should find, in place of the infarction, 

 that sharply-defined and regular loss of substance, to which 

 CruveiUner gave the name of " erosion hemorrhagique.'' 



§ .^j73. I agree with many other observers in assigning a 

 similar mode of origin to the simple (chronic, circular, perforat- 

 ing) ULCER OF THE STOMACH. On IJecembcr 4th, 186."), a man 

 was admitted into the surmcal wards at Bonn with a stran^ju- 

 ]ated inguinal hernia. He had bee?-; vomiting continually fi'om 



