X.] PANCREATIC DIGESTION. 79 



14. Chemical Examination of the Gastric Contents, e.g., Vomit. 



(a.) Test the reaction. 



(6.) Determine the acidity (e.g., of 10 cc.) by means of a deci-normal solution 

 of caustic soda. (See "Urine.") 



(c.) Test 10 cc. for the presence of pepsin (digest with fibrin and HC1), and 

 rennet (milk). 



(d.) Use the tests 9 (c.}, (d.), (.), for determining the presence of free 

 HC1. 



(<?.) Make a rough estimate of the presence of lactic, butyric, and acetic acids 

 by the method 9 (<?.). 



(/.) Examine for proteids, e.g., albumin, albumoses, and peptone. 



(g.) Test for sugar and its digestive products. 



(A.) Distil some of the fluid, extract the remainder with sulphuric ether, and 

 in the latter estimate the lactic acid which it contains. 



('.) Test Meal. When it is desired to know it digestion is normal a 

 test- meal is given. Ewald recommends a roll of stale bread taken on an 

 empty stomach, with tea or water. After an hour the contents of the stomach 

 are pumped out by means of a stomach pump, and examined as above. 



LESSON X. 



PANCREATIC DIGESTION. 



1. Preparation of Artificial Pancreatic Juice. 



(a.) Mince a portion of the pancreas of an ox twenty-four hours 

 after death, rub it up with well-washed fine sand in a mortar, and 

 digest it with cold water, stirring vigorously. After a time strain 

 through muslin, and then filter through paper. The filtrate has 

 digestive properties, chiefly upon starch. Instead of water, a more 

 potent solution is obtained by digesting the pancreas at 40 C. for 

 some hours with a 2 per cent, solution of sodic carbonate. To pre- 

 vent the putrefactive changes which are so apt to occur in all 

 pancreatic fluids, add a little 10 per cent, alcoholic solution of 

 thymol. 



(b.) Make a glycerin extract of the pancreas (pig) in the same 

 way as described for the stomach (Lesson IX. 1, I). Before 

 putting it in glycerin, it may be placed for two days in absolute 

 alcohol to remove all the water. The glycerin extract acts on 

 starch and proteids. 



