ACUTE GASTRO-INTESTINAL CATARRH IN THE HORSE. 69 



The function of the horse's stomach is specially favored by a solu- 

 tion of hydrochloric acid of 2 : 1000, which may be replaced by a 

 lactic acid solution of 2 ; 100 ; the same effect is obtained by a 

 1 : 1000 solution of hydrochloric acid, added to a 5 : 1000 solution 

 of lactic acid. When the hydrochloric acid concentration exceeds 

 the proportion of 5 : 1000 the pepsin action is lost, and the excess 

 of lactic acid may produce catarrh of the stomach (Ellenberger and 

 Hofmeister). Admitting the normal contents of the stomach to be 

 10 litres, the proper dose of hydrochloric acid will be 20 grammes 

 (in a solution of 2 : 1000), supposing that there was no trace of this 

 acid in the stomach. 



6. The action of pepsin is favored by water and a temperature 

 of 37° to 55° C. Cold is therefore hurtful. The inflamed mucous 

 membrane of the stomach does not furnish any pepsin. Exaggerated 

 quantities of pepsin interfere with digestion (Ellenberger and Hof- 

 meister). 



7. Epidermic productions are not digested by the horse, viz., 

 epidermis, hair, feathers, wool, nails, and horn ; the same is true 

 of wax (wax pills !). Bones, elastic tissues, straw, bran, and cellu- 

 lose, especially when these substances are old, can only be digested 

 with difficulty. 



8. The normal peristaltic movements of the stomach assist diges- 

 tion by increasing the secretion of the gastric juice and producing 

 a more thorough mixture of the alimentary matters. When these 

 movements are no longer produced, on account of weakness of the 

 stomach, or the participation of the muscular wall in the inflamma- 

 tion of the mucous membrane, digestion is interfered with, dilata- 

 tion of the stomach takes place, etc. The peristaltic movements 

 are also suppressed when hydrochloric acid gives out, for this agent 

 is the principal stimulant of gastric action. 



9. The mucous membrane of the stomach is protected from the 

 digestive action of the gastric juice: by the blood which irrigates 

 the mucous membrane abundantly, the alkaline property of which 

 counteracts the acidity of the digestive fluids; by means of a coat- 

 ing spread upon the surface of the mucous membrane, and finally, 

 by the gastric epithelium. 



[That the stomach is capable of digesting all albuminoid sub- 

 stances and yet escapes auto-digestion is a fact that has never 

 yet been satisfactorily explained ; if the alkalinity of the blood 

 neutralizes the gastric juice and prevents self-digestion of the 



