formed some experiments on the solution and removal of pepsine by water from the healthy stomach. Fortyeight hours after food had been given to a dog, half a pint of water at the temperature of the body was injected through an œsophageal tube into the stomach. In a quarter of an hour's time the life of the animal was destroyed, and the liquid immediately collected from the stomach. The organ was quite devoid of food, but found to contain a little hair and some small fragments of straw. The liquid presented a strongly acid reaction; and, experimented upon alone, gave evidence of possessing digestive power. In another experiment, at the same period after the administration of food, six ounces of water at the temperature of the body were introduced into the stomach, and in five minutes' time the animal was killed. The contents of the stomach, which were immediately collected, were found neutral to test paper, as also was the mucous surface. Treated with an acid, the liquid obtained produced a strong digestive action in respondence to the test that was employed. In the first experiment it would seem that the water during its quarter of an hour's sojourn in the stomach had excited a little flow of acid secretion from the follicles; whilst in the second, where five minutes only were allowed, pepsine was dissolved out from the mucous surface, but no acid had made its appearance.

Pyrosis, as a rule, only constitutes a functional disorder, and is not in itself a grave affection. It sometimes, however, occurs as a concomitant of organic disease, upon the nature of which the gravity of the case will then depend. Persons who have once been affected with pyrosis are very apt to experience a

recurrence.

Opium is a remedy to which pyrosis generally yields. It relieves the pain; and, by allaying the morbid irritability of the stomach, checks the excessive secretion, which forms the prominent feature of the complaint. Sir Thomas Watson recommends opium in combination with an astringent, and says that the compound kino powder of the London Pharmacopoeia is an admirable remedy for pyrosis. In the out-patient department of a metropolitan hospital, the physician is frequently called upon to treat this affection, and the prescription I am in the habit of ordering at Guy's and am not disposed to forsake, is one containing opium in combination with a bitter. The following is the formula employed, and such is the success with which it has been used, that I am frequently remarking to students attending in the out-patient room that I have rarely, if ever, known it fail in rapidly affording relief:

B Liquoris Opii Sedativi, mviij;

Inf. Gentianæ co., 3j.

Misce, fiat haustus ter quotidie sumendus.

It often happens that other indications of gastric derangement accompany pyrosis. These will require their appropriate treatment as soon as the pyrosis has been subdued. Any article of food that is known to constitute an exciting cause of the complaint must be abandoned, or the relief afforded by treatment will only be of a temporary description.

ACIDITY.

Disordered digestion is sometimes attended with acidity of the stomach as its prominent symptom. The person experiences, in some instances occasionally only, in others almost constantly, a sour taste in the mouth. Acid eructations occur whilst digestion is going on, and the acidity of these eructations may be such as to set the teeth on edge. If the condition

exists for some time, the teeth indeed become acted on and destroyed. Everything that is taken may be found to "turn more or less sour on the stomach;" but it is discovered that some articles of food are more productive of acidity than others. Vegetables, pastry, sweets and fruit, for example, are of this class. It sometimes happens that it is only after partaking of articles of this kind that the acidity is experienced. In the gouty diathesis a predisposition exists to the occurrence of this derangement.

It is well known that the saccharine principle is convertible by a particular kind of fermentation into acid. This conversion being permitted to occur within the stomach, through the existence of a defective state of its secretion, will account for some of the acid generated namely, that which is specially produced by food of a saccharine and farinaceous description. But

marked acidity is in some cases experienced after the exclusive consumption of animal food; and hence it must be inferred that an excessive elimination of acid as the result of secretion may constitute also a source of the complaint.

Under healthy circumstances, changes of ordinary fermentation and putrefaction are not permitted to take place within the stomach, on account of the antiseptic power which the gastric juice enjoys; but when gastric juice imperfect in quality or deficient in quantity is secreted, fermentative changes in the food fail to be prevented from occurring; and so, the production of acid results. Again, from obstruction in the neighbourhood of the pylorus, or from some other cause, the food may be delayed for too long a time within the stomach, and the generation of acid that would not otherwise have taken place be permitted.

A morbid irritation of the stomach arising from disease, as from ulcer or cancer; or from the presence of indigestible articles within its cavity, may lead to an undue action of the secreting apparatus; and thus, an excessive outpouring of acid. The irritation resulting from disease may even cause gastric juice to be secreted during an empty state of the organ. Further, a source of irritation existing in some other part may affect the stomach in a reflex manner, and cause like direct irritation of the organ, a flow of gastric juice to take place without the usual stimulus being supplied. Such, for example, has been found to occur during the passage of gall stones through the bile ducts; and in the gastric disorder so common in organic diseases of the brain and tubercular disease of the lungs.

Alkalies and the alkaline earths-as the carbonates of soda, potash, and lithia; magnesia; and lime water— taken about two or three hours after a meal, by neutralising the excess of acid existing, afford a temporary relief to the complaint. The fluid magnesia (Liq. Magnesiæ Carbonatis of the British Pharmacopoeia) forms an agreeable and serviceable antacid. The Vichy, Vals, Seltzer, and lithia waters, may often also be advantageously resorted to. By the continued administration of these remedies, a permanent removal of the morbid condition may be oftentimes brought about, but in other cases a temporary relief is all that continues to be afforded; and there are many persons who are constantly in the habit of resorting to the use of the carbonate of soda, which is the popular remedy employed, to correct their acidity of stomach.

Where the alkaline treatment fails, the mineral acids, by acting as tonics and improving the digestive power will sometimes effect a cure. The nitric acid in particular, says Abercrombie, is often found to be one of the best correctors of acidity. Where gout exists, colchicum is likely to do good.

As in the treatment of the other manifestations of deranged digestion, attention must be paid to the food and drink that are taken. A careful regimen will often succeed by itself in removing; and, if it do succeed in removing, will always lessen the complaint. Vegetables, fruit, pastry, and sweets, being the articles most productive of acidity, are to be looked upon as the things particularly to be avoided. Toasted and pulled bread agree better than bread of the ordinary form. Of animal food, broths and soups are the most