THE GASTRIC JUICE. 



24S 





Bordeaux wine, treated with amylic alcohol until its colour almost disappears, becomes rose- 

 coloured. [Giinzburg recommends an alcoholic solution of phloroglucin-vanillin. 2 grammes of 

 phloroglucin are mixed with 1 gramme of vanillin in 30 grammes of absolute alcohol, which gives a 

 yellowish-red solution. Concentrated and even very weak mineral acids cause, with this solution, 

 a bright red colour with the formation of bright red crystals, while concentrated organic acids 

 do not affect it. For gastric juice mix equal quantities of the filtered gastric juice and the 

 above solution in a watch-glass, and evaporate carefully, not allowing it to boil; a red pellicle 

 with red crystals indicates the presence of minute traces of hydrochloric acid. Congo-red, 

 either in solution or as congo-red papers, becomes blue, but the reaction is interfered with by 

 the presence of ammonia, or ammoniacal salts.] 



Lactic Acid. The freshly-prepared blue solution of 10 c.c. of a 4 per cent, solution of 

 carbolic acid, with 20 c. c. of distilled water, and 1 drop of liquor ferri perchloride, is changed to 

 yellow by lactic acid ( Uffelmann). 



Fig. 183. 

 Section of the pyloric mucous membrane. 



Pyloric glands showing changes of the 

 cells during digestion. 



(3) The large amount of mucus covering the surfa'ce of the mucous membrane is 

 secreted by the goblet-cells of the mucous membrane ( 162), ( 136, II.). 



(4) Mineral salts (2 per 1000), and a milk-curdling ferment. 



They are chiefly sodium and potassium chlorides, less calcic chloride (ammonium chloride, 

 also in animals), and the compounds of phosphoric acid with lime, magnesium, and iron. 



Amongst foreign substances, which may be introduced into the body, the following appear 

 in the gastric juice HI, after the use of potassium iodide potassium sulphocyanide, ferric 

 lactate, and sugar ; and ammonium carbonate in uraemia. 



