HANDBOOK FOE BIO-CHEMICAL LABORATORY. 33 



solution together with pepsin, although a small portion of for- 

 eign matters, nucleins, antialbumid, etc., remain undissolved. 

 The liquid is filtered and saturated with powdered (KE 4 ) 2 S0 4 , 

 when a precipitation of the albumoses with the pepsin occurs. 

 The precipitate is collected on a filter, washed with a saturated 

 solution of ammonium sulphate, and then dissolved in 0.2$ 

 HC1. Add 0.25$ thymol to this acid solution and dialyze in 

 running water until the whole of the (NH 4 ) 3 S0 4 is removed. 

 On opening the dialyzing tubes a precipitate is found, which 

 is soluble in 0.2$ HC1 and furnishes a very active gastric 

 juice. (Eiihne and Chittenden.) 



2. The mucous coat of a freshly removed pig^s stomach is 

 carefully washed with water and finely divided, or, if a calf's 

 stomach is employed, only the cardiac region is scraped with 

 a watch-glass or the back of a knife. The pieces of the 

 mucous coat or the slimy masses obtained by scraping are 

 rubbed up with pure quartz sand or glass powder, treated 

 with water, and allowed to stand for 24 hours in a cool place- 

 On filtering, an opalescent liquid is obtained, which, when 

 acidulated so as to contain 0.1-0.2 per cent HC1, possesses 

 powerful digestive activity. (Kuline.) 



3. The stomach of a pig is opened, emptied, and then the 

 surface cleaned with a wet sponge (running water will dissolve 

 out a considerable part of the pepsin). The mucous mem- 

 brane is removed from all but the pyloric end of the organ. 

 It is then freed from a portion of the water adhering to it by 

 pressing between dry cloths and then mincing. The finely 

 divided mucous membrane is then placed in two or three litres 

 of dilute HC1 containing from 6 to 10 c.c. strong HC1 per litre, 

 and the mixture is digested in an incubator at a temperature 

 of 35-45 C. for a period varying from a few hours to a day. 

 If sufficient fluid be present and the mixture now and then 

 shaken, all ought to be dissolved in a few hours, leaving but a 

 small quantity of brownish flakes and some mucus undis- 

 solved. The liquid is filtered through paper, and then may 



