THE FRACTIONAL METHOD OF GASTRIC ANALYSIS 217 



logical active gastric juice with an average total acidity of 30 

 and an average free acidity of 18.5. The residuum is often colored 

 by bile. This is particularly true if the fluid has a relatively high 

 acidity. Trypsin is also generally present. These findings indicate 

 regurgitation. Pathological residuums may contain blood, pus, 

 mucus and may show food retention which is indicative of dis- 

 turbed food evacuation. The quantity may also be much increased 

 due to hypersecretion. A residuum of large volume possessing 

 a total acidity value of 70 or over may indicate ulcer. 



3. The Test Meal. Before making an analysis of the stomach 

 contents it is customary to introduce something into the stomach 

 which will stimulate the gastric cells. The response to this stimu- 

 lation is then measured clinically by the determination of total 

 acidity, free acidity and pepsin in the stomach contents. Many 

 forms of test meal have been used. 



The test meal most widely employed is the Ewald test meal. 

 This consists of two pieces (35 gms.) of toast and 8 ounces (250 

 c.c.) of tea. 



Inasmuch as it has been demonstrated in Hawk's laboratory 1 

 that water gives a similar gastric stimulation to that produced 

 by the Ewald meal it is suggested that a simple water meal might 

 be substituted for the Ewald meal. This water meal also has the 

 added advantage of enabling one to determine the presence of 

 food rests and to test more accurately for lactic acid, blood, and 

 bile. 



4. The Retention Meal. In order to obtain more information 

 regarding gastric motility than is furnished by the ordinary test 

 meal described above the patient may be fed a so-called retention 

 meal. This meal is fed in place of the regular evening meal and 

 contains substances readily detected. In the morning before 

 breakfast (7 to 8 A.M.) remove the stomach contents (residuum) 

 by aspiration and examine for food rests. The normal stomach 

 should give no evidences of food retention. A satisfactory reten- 

 tion meal consists of 4 ounces each of boiled string beans and 

 rice. Diets containing prunes, raspberry marmalade, lycopodium 

 powder, etc., have also been employed. In many instances an 

 ordinary mixed diet will serve the purpose. 



5. Removal of Samples for Analysis. At intervals of exactly 



1 Bergeim, Rehfuss, and Hawk: Jour. Biol. Chem., 1914, 19, 345, and 

 Rehfuss, Bergeim and Hawk: Jour. Am. Med. Assn., 1914, 63, 11. 



