viously determined) of NaOH, boiled, acidified with acetic acid, five c.c. saturated solution of NaCl are added, and the mixture is again boiled, washed with enough distilled water to make 150 c.c., and filtered after it has become cool. (Oppler makes a control test at the same time.) The quantity of nitrogen is estimated in 50 c.c. of the filtrate by the Kjeldal method, and the result is multiplied by three. The quantity of nitrogen in the dilution of the contents-and in the H,SO, used as a reagent-is deducted. The remainder is the quantity of digested albumin. If, for example, the solution of eggalbumin contains 2.1 per cent. albumin, and 50 c.c. of the diluted (one liter) total gastric contents contain 77.5 milligrams of N, and the 50 c.c. of the test digestion filtrate contain 22.4 milligrams of N, then 22.4 X 3, or 67.2 milligrams of N have been digested. Of this quantity 17.5 milligrams are already present in the gastric contents. Consequently, the remainder, after this is subtracted, when multiplied by 5 (20 c.c. being used), is equal to the quantity of the albumin in 100 c.c. of the test albumin solution which has been digested. The 248.5 milligrams of N are equal to 1.55 gr. of albumin, which is 74 per cent. of 2.1. That is, the digestive power is a little greater than normal (70 per cent.), or a little more than twice as great as the digestive power (35 per cent.) of the 1: 1000 solution of pepsin.

The Practical Value of the Pepsin Signs.-Pepsin may be formed in normal, in excessive, or in subnormal quantity. A continuous normal pepsinogen secretion is a good sign of the integrity of the glandular layer; but a mild anatomical disease of the stomach may be present without causing a noteworthy change in the quantity of pepsin.

Pepsin, contrary to the common belief, may be secreted in excessive quantity. This excessive secretion is often met with in chronic hypersthenic (glandular) gastritis. The early morning contents of continuous secretion often digest more rapidly than the contents obtained after a test-meal given to the same individual. The fluid of gastric retention with free HCI usually digests better when diluted and acidulated with HCl. But if the irritation and continuous secretion and the accumulation of ferments be controlled for a few days by diet and lavage, the actual diminished power of secretion may be made clear in some cases of gastric retention. Consequently an excess of pepsin may be due to the secretion of a gastric juice which is excessively rich in it or to its accumulation in the stomach. In both instances the tests of Hammerschlag and Oppler give an increase of digestive power,

and the dilutions likewise digest more albumin than do similar dilutions of the test-breakfast contents. Whenever the filtrate of the early morning contents possesses greater digestive power than the filtrate of the test-breakfast contents, there is motor insufficiency. In simple continuous secretion, the early morning contents possess no greater digestive power than the contents after the test-breakfast, and the specific gravity is that of the gastric juice-1004 to 1006.

In still another condition the pepsin tests are valuable, as when there is persistent and progressive diminution of the specific elements of secretion. This is a physical sign of chronic asthenic gastritis, of atrophy of the gastric glands, or of carcinoma. But pepsin secretion is commonly diminished in chronic inanition, and variations of quantity occur in consequence of nervous influences, particularly in hysteria and in adenasthenia gastrica. Consequently, not even a great diminution of the secretion of this ferment should be considered pathognomonic of severe glandular disease without other corroborative signs. The diminution of pepsin is not characteristic of any particular disease of the stomach, and its quantity varies in very close relation with the quantity of total HCl. Consequently, its increase or decrease or its presence in normal quantity in the contents after the testbreakfast possesses about the same significance as like states of HCl secretion. But there is no doubt that the diminution and the loss of labferment secretion are very grave signs and are much less frequent than the diminution and loss of hydrochloric acid and pepsin secretion.

3. MUCUS, OR THE GENERAL SECRETION.

The general secretion of the stomach is mucus, a product of the cylindrical cells which thickly line the surface and extend a short distance into the peptic glands and line completely the mucus glands. This secretion forms a very important protection to the delicate structures which it normally covers as a thin layer. In catarrh, the quantity of the mucus may be greatly increased, and forms, particularly about the pylorus, very thick masses, either clear and tough with at pale membrane beneath or tinged with blood and mixed with the exudate from the hyperemic blood-vessels.

The mucus which is secreted by the normal cylindrical surface epithelium contains only a trace of mucin, and no cloudiness is produced by the addition to it of either distilled water (dilution) or acetic acid. It is readily dissolved and

digested by the gastric juice. Consequently, the chemical test of normal gastric mucus is worthless, and the search for excessive mucus secretion should be made, not in the testmeal contents, but in the early morning wash-water. In the morning before breakfast 1⁄2 of a pint of water is allowed to flow in and out of the stomach (siphonage) several times, and this wash-water is examined for mucus. The stomach mucus will then appear in shreds and in flocculent masses mixed with a few fat droplets, starch granules, and cylindrical epithelial cells. It stains but faintly with methyl-green and thionin, and it swells, instead of coagulating and contracting, on the addition of acetic acid. The gastric mucus, however, which is formed after the transformation of the cylindrical into goblet cells (gastritis), contains more mucin, and consequently stains more intensely and precipitates on the addition of acetic acid. The presence of much mucus in the washwater or in the stomach-contents delays filtration, and large quantities of it may be left on the filter. The greatest quantities of mucus are found in asthenic and atrophic gastritis and in carcinoma. It accumulates because it is secreted in excess, contains more mucin, and is not dissolved by digestion. The quantity of undissolved mucus is in inverse proportion to the quantity of HCl and pepsin. The persistent secretion of mucus in excess is a distinctive sign of gastritis-be the gastritis primary or secondary, acute or chronic, asthenic or hypersthenic, or atrophic.

The mucus removed from the stomach may have been swallowed. The swallowed mucus forms glairy lumps, mixed with squamous epithelium and often with pus cells, and it frequently floats on the surface. The stomach mucus occurs in shreds or flocculent masses, is mixed with starch granules, contains cylinder or beaker cells or their nuclei, and only a few leukocytes. The collection of mucus in the stomach may in reality be an accumulation of saliva. The saliva may be detected by the reaction of the sulphocyanid of potassium which it contains with iron. A dilute solution of chlorid of iron is added, drop by drop, until the red color which is produced no longer increases in intensity. The coloration remains after the addition of hydrochloric acid and is not discharged by bichlorid of mercury, otherwise the red color is not produced by saliva.

2. THE MOTOR FUNCTION.

The gastric muscle plays an exceedingly important part in the pathology of the stomach. Motor insufficiency is a serious primary trouble, and likewise a serious complication. The cardiac muscle has recently been given its proper place in the pathology of the heart. For a long period attention was directed chiefly to the valves and to the pericardium; the heart muscle was neglected. But the involuntary muscular system deserves a more prominent place in internal pathology. Attention has been directed too exclusively to the mucous membrane. But the uterine muscle is no more important in labor, nor the heart muscle in the circulation of the blood, than is the gastric muscle in digestion. The integrity of the muscle cells is no less important than that of the cells which secrete.

When the general strength and nutrition are affected in an unfavorable manner by a disease of the stomach, this result can usually be attributed to a motor defect, which, unlike secretory insufficiency, can not be compensated. The chemical work of the stomach may be null without affecting nutrition if the integrity of the motor function is maintained and the contents of the stomach are given over to the healthy intestines for digestion and assimilation. The intestinal juices are much more powerful and active than the gastric secretion. This is the teaching of operations on the stomach which simply secure the passage of the food into the intestines; such is also the teaching of experiments on animals and of pathology.

The movements of the stomach are two-the evacuating and the churning. The movements are in all probability due to the excitation of the ganglia in its walls, through which the vagosympathetic branches which go to the stomach probably also exert their influence. The stimulant of these movements is not HCl only; the movements continue when the reaction is neutral, but are excited by the various elements of the contents.

The movements of the stomach during digestion and the process by which the organ empties itself have long been the subject of careful study. The character of these movements is no less a matter of controversy than is their explanation. The philosophy of the subject may be left out of account in a clinical work and only the results of observations need be gathered.

Viewed from the results, the contraction of the muscular layer of the stomach produces a twofold effect-the increase of intragastric pressure and the motion of the contents. The fibers the contraction of which causes these results may act contemporaneously and in union or separately and independently.

During the first period of digestion, the duration of which is dependent upon the physiological action of the food, the tonic contraction predominates, and the motionless gastric wall applies itself closely to the gastric contents. This period of high intragastric pressure may last a few minutes or two or three hours, the duration being determined by the physical and chemical qualities and the physiological action of the contents and by the power of those fibers which have to do with the result.

The second period is that of the worm-like movements, which are cardiac, pyloric, or total, according to the location and extent of their visible expression.

The movements of the cardiac portion begin at the cardia, are slow and weak, and lose themselves in the middle of the organ. These peristaltic movements may be contemporaneous with those of the pylorus or they may be alternating. Observation has established between them no law.

The movements of the pyloric end are more complex. Two forms have been observed and may be accepted as physiological: First, those which begin on the cardiac side of the pylorus and become stronger as they pass forward and disappear in the duodenum; second, those which begin on the descending portion of the duodenum and move backward on to the stomach, in the middle third of which they are lost, soon to reappear with greater power along the pylorus to the duodenum. The character of these movements forms the basis of a theory which maintains that the opening of the pylorus is due to a cause which has its origin in the duodenum.

The total movements are exclusively peristaltic, and begin at the cardia and move slowly toward the pylorus, near which the wave becomes higher and more rapid. The effect of the peristalsis is more visible along the greater curvature, the thick longitudinal bundle along the lesser curvature serving as the fixed line of attachment. These lesser curvature longitudinal fibers extend to the duodenum, over the upper and anterior surfaces of which they spread. Their contraction would tend to straighten the line between the cardia and the more immovable duodenum, and, if not counteracted by contraction of the ring fibers, it would open the pylorus.