The motor power of the stomach is demonstrated in various ways.

Leube's Method

Leube's method is to empty the stomach after the ingestion of a Leube's test dinner (p. 523), or Ewald's test breakfast (p. 523). If the stomach is empty three hours after the former and one and a half after the latter, hypermotility is present - i. e., the food is being too rapidly hurried into the duodenum. If undigested food remains six or seven hours after eating the Leube test dinner, the motility is impaired, and the diet must be regulated accordingly. (See Chronic Gastric Catarrh, p. 540, and Dilatation, p. 546).

Ewald And Siever's Method

Another method, that of Ewald and Siever's, is very simple, but not very reliable. Fifteen grains of salol are given in a wafer immediately after a meal, and the urine is tested for salicyluric acid, which is derived from salicylic acid formed in the alkaline intestine as one of the products of dissociation of salol. Salol escapes being acted upon by the gastric juice, and the salicyluric acid appears in the urine half an hour or an hour after it is swallowed if hypermotility be present - otherwise, not for several hours. The salicyluric acid is readily detected by the violet colour which appears in the urine on adding a drop or two of ferric-chloride solution. The chief difficulty in the performance of the test is in getting urine when wanted without catheterisation. Frequent catheterisation merely for the purposes of such a test is to be condemned, and patients cannot usually micturate every fifteen minutes. Brunner and Huber prefer to make the test dependent upon the disappearance of all trace of salicyluric acid after ingestion of one gramme of salol.

Normally it can be detected for only twenty-four hours, but if the motor power of the stomach is impaired it may be obtained as late as forty-eight hours after.

Bourget found that the reaction time is delayed an hour or more by giving a dose of HC1 with a meat meal, whereas it is accelerated by a less acid meal of which fruits and vegetables form a part.

Stewart, in referring to this experiment, points out that hyperacidity of the gastric juice, by neutralising the duodenal juices, might retard the salol reaction without the existence of motor insufficiency.

Klemperer's Method

Klemperer has the patient swallow one hundred grammes of olive oil into an empty stomach, or the oil may be poured in through a stomach tube. It is left for two hours, and then the stomach contents are washed out. The oil is abstracted from the washing with ether, and the ether is separated. The oil is then measured. Between seventy and eighty grammes of oil should pass on into the intestine inside of two hours, but if it has not done so there is lack of motility.

Sahli has devised a test meal of a soup of butter, flour, salt, and water to test the mobility and other functions of the stomach, but its preparation and use is too elaborate for ordinary clinical purposes.