134 CONTENTS OF THE INTESTINAL CANAL. 



round ulcer of the duodenum where vomitingoccurs four or six hours 

 after food has been taken, we constantly find that not only the 

 albuminous substances, but also the amylacea, are far more changed 

 than in perforating ulcer of the stomach; in scirrhus of the 

 pylorus, on the other hand, they are usually less changed than in 

 other cancerous affections of the stomach, &c. These changes 

 which we perceive in the food must either be normal or abnormal, 

 that is to say, in the first case we find half-digested muscular 

 fibre, peptones, sugar, &c., changed in the manner which has been 

 already described. These are the rarer cases, and for the most part 

 occur when the seat of the disease which has occasioned the vomit- 

 ing lies externally to the stomach, although sometimes also in 

 cancer of the stomach. It far more frequently happens that the 

 food, when it has remained for a prolonged period in the stomach, 

 has undergone abnormal changes; if saccharine or amylaceous 

 food has been taken, lactic, acetic, or butyric fermentation is 

 induced, in which case the vomited matters have an extremely 

 strong acid reaction and taste, and even seem to take the edge off 

 the teeth; the nitrogenous articles of food appear, in this case, 

 when examined under the microscope, to be but slightly changed, 

 and at most to be only loosened in texture and rendered more 

 transparent; matters of this nature are principally vomited in 

 chronic gastric catarrh, but not unfrequently also in round (per- 

 forating) ulcer and in cancer of the stomach. It seems probable 

 that in chronic catarrh of the stomach, all those kinds of fermenta- 

 tion may be set up in the starch, according to the nature of the 

 secreted mucus, which we are accustomed to observe out of the 

 animal body in the laboratory of the chemist, just as in catarrh of 

 the urinary bladder there is sometimes a predisposition to acid and 

 sometimes to alkaline urinary fermentation. Certain experiments 

 made by Frerichs show that in diabetic patients there is a special 

 tendency to the formation of sugar in the stomach. Another of his 

 observations is even more important ; he convinced himself that 

 the colourless, viscid, ropy masses, which are sometimes ejected 

 in abundant quantity in gastric catarrh, possess almost entirely 

 the same properties as the gum-like substances produced by what 

 is called mucous fermentation. It appears to depend, at all 

 events in part, on the nature of the mucus secreted in gastric 

 catarrh, whether the fermentation established in the amylacea be 

 of the mucous, lactic, acetic, or butyric variety a view which 

 seems to correspond with our present knowledge of the exciters 

 of these different kinds of fermentation, and with the different 



