CHAPTER III. 

 GASTRIC DIGESTION. 



I. Detection of Hydrochloric Acid in the Gastric Juice: 



(a) .with methyl violet; (6) with tropseolin; (c) with Guns- 

 burg's reagent. 

 II. Detection of Lactic Acid (and Hydrochloric Acid) : 



(a) by Uffelmann's method ; (6) after extraction with ether. 



III. Detection of Pepsin in Gastric Juice or Vomit. 



IV. Influence of the Amount of Pepsin on the Intensity of Digestion. 

 V. Influence of Disturbing Substances, Qualitative. 



VI. Comparison of Different Kinds of Pepsin. 

 VII. Preparation of the Products of Digestion. 



I. DETECTION OF HYDROCHLORIC ACID m THE GASTRIC 



JUICE. 



Solutions required: 



1. Six cubic centimeters of strong hydrochloric acid, 

 specific gravity 1.19 (about 37 per cent. HC1), diluted to 

 one liter: solution A. This solution contains 0.27 per 

 cent, of HC1. 



2. One hundred cubic centimeters of solution A diluted 

 to 500 cc.: so\utlon B. 



3. Eight-tenths of a gram of lactic acid dissolved in 100 

 cc. of water. 



4. Two grams of commercial peptone dissolved in 100 cc. 

 of water. 



33 



