healthy exercise the living organism in all its working powers.

There are medicinal substances, however, which, in their stimulant and tonic character, serve to assist in exciting the vaso-motor nerve to more energetic action.

On the Hypodermic use of Remedies, and Inhalation. -As the most easy method by which medicines can be absorbed is through the stomach, it is generally made to bear the presence of agents which greatly interfere with its own function. Thus astringents are applied to its surface, whilst it is often expected to exert its full energy; irritants are brought into contact with it; alkalies neutralise its secretion, and thus destroy the solvent power of the gastric juice; opiates deaden its sensibility, whilst they also check its secretion. It must be confessed that the stomach is often used amiss. It is overtaxed in health, and during the progress of disease, whilst it suffers as part of the general system, it is made to bear the presence of all kinds of remedial agents a sort of living fulcrum on which the physician exercises his powers of controlling and staying disease. But although generally a willing agent, it sometimes becomes rebellious and uncontrolable. Other methods, however, are in use, and may be applied with some prospect of success. There is the epidermic, as well as the endermic mode of administering remedies. The use of enemata might be employed more frequently than it is with great benefit, and the inhalation of remedies is a

method that has been often lost sight of because more troublesome in its application. As to the epidermic method, a thick layer of epithelium renders absorption very slow, so that this is one of the most tardy means of inducing medicinal action. Continuous contact upon the surface of the skin is used, as when a belladonna plaister is applied, or iodine pencilled upon the part affected; or inunction is employed, as when oleaginous substances are rubbed in, whether of a simple kind, or containing irritants, as croton oil; or the remedy may be used in the form of a bath, as the sulphurous or nitro-hydrochloric acids, and in this way nutrient material has been introduced into the system, as by bathing, or placing portions of the body in milk.

The endermic or hypodermic method has of late years been extensively employed, first, by Kurzack, Reid, and Rynd, for the relief of symptoms by local injection into the skin, and then for the production of general symptoms by Dr. Hunter. Modern chemistry has so separated the active principles of many medicines in the form of vegetable alkaloids, that a full dose may be administered in a very small quantity of solvent; and it must be borne in mind that the hypodermic method ensures the most rapid absorption into the system; a smaller dose is therefore required to produce the same effect as that produced by ordinary absorption from the mucous membrane. A quarter of a grain of morphia might be taken with comparative impunity by an adult,

but the injection into the cellular tissue of this minute quantity has been known to induce almost fatal coma. The best means of employing hypodermic injection is by the aid of a carefully regulated syringe, armed with a perforated needle extremity. Quinine, atropia, and aconite may be used by this method, but the latter alkaloids require extreme care.

Amongst the valuable remedies we possess for the relief of gastric disease, there are some which have in many instances, by their improper employment and abuse, produced serious results; we refer especially to the unwise use of alkalies, purgatives, mercurial medicines and ardent spirits.

Alkalies. Some of the familiar symptoms of gastric disorder are correctly attributed to an excess of acid in the stomach, whether from direct secretion of gastric juice, or from secondary formation consequent on chemical reaction. Heartburn, and other allied conditions, thus induced, are often immediately relieved by the carbonated alkalies of potash, of soda, or of magnesia; and many persons on the return of the symptom at once resort to this palliative measure, and repeat the alkaline remedy, or the habit is acquired by some of taking an alkali after nearly every meal. In this way the solvent power of the gastric juice is greatly interfered with, for its natural acidity is destroyed; and we have known a state of general weakness and exhaustion gradually induced by such practice.

The excessive use of

There are also other conditions in which alkalies are given with advantage, even in large doses, and for a considerable time; we allude to the presence of calculus in the kidney, to diseases of the bladder, to gouty dyspepsia, and to rheumatism, &c. alkalies, even in these cases, greatly injures healthy digestion, and is followed by exhaustion, pallor, irritability of the nervous system; the blood is apparently changed in character, and the relative quantity of the red corpuscles diminished. As an alkaline salt, the chloride of sodium, common salt, is an important ingredient of our ordinary food; but in excessive quantities it is not only an irritant, but when by habit the mucous membrane can tolerate its presence, the blood is changed, and we have seen marked purpurous spots covering the skin from this cause. A patient had been in the habit of thickly spreading table salt on his bread, morning and evening, nearly a quarter-of-aninch in thickness; the purpura disappeared when the habit was discontinued, but he felt it a great deprivation to be debarred from his baneful excess of salt.

The salts of magnesia have in some instances been found in concretions in the intestine, but it is only when the carbonate or the simple magnesia have been taken in very large quantities, or for lengthened periods, that such result has followed.

Purgatives.-Few remedies afford greater relief in many forms of dyspepsia, especially those connected

with portal and hepatic congestion, than a free purgative action on the bowels; a sense of depression and exhaustion is often associated with congestion of the biliary organs, and free action is followed by renewed feelings of healthy elasticity and strength. This circumstance has led to the too frequent use of the Abernethian remedy of a blue-pill and black-draught; and it is unfortunately given when an opposite plan of treatment is required.

Again, it has been supposed that a daily relief from the bowels is essential to health, and purgatives are often given to induce this action; and when, especially in early life, constipation becomes obstinate, purgatives are unfortunately repeated, and persisted in, so as to compel a continuous effect. Irritation of the mucous membrane is the result of this mal-treatment; and we have frequently witnessed chronic inflammation of the colon, and the discharge of mucous secretion induced, so as to trouble the patient for many months.

The stimulus thus acting upon the alimentary tract must be repeated to produce similar action, and the strength of the remedy is gradually increased; inactivity of the bowel follows, with distension; for, with increased size, greater contractile power in the involuntary muscular fibre is required. This distension of the colon is a troublesome and distressing symptom, the abdomen is enlarged, the stomach is pressed upon by