its administration is safe because, the physiological action of the drug giving warning of danger, its use can be stopped in time to prevent accidents. In cardiac patients where there is excessive hypertrophy, and drugs of the digitalis class are contra-indicated, it is less advantageous than aconite, which is more persistent in its effects and not so apt to cause gastric disturbance, but in other affections where the aim is to reduce arterial action it is held in deservedly high repute. Thus, in the early stages of sthenic infectious pneumonia it has long been considered one of the most reliable of remedies, quieting the increased action of the heart, lowering the temperature, and lessening the congestion of the lung. It should, however, be administered only to young adults who are robust and possess an excellent circulatory apparatus. It may also be used with advantage, if given sufficiently early, when only hyperæmia is present, in pleurisy, hepatitis, cerebritis, maniacal delirium, and in mania à potu, with strong, bounding pulse, and other sthenic conditions. If its employment is maintained after the primary stage of congestion, however, it can only do harm. In acute gastritis and peritonitis it is generally contra-indicated on account of its irritating effect upon the stomach, though in peritonitis it may sometimes be of service if carefully watched. In aneurism where there is marked disturbance of the circulation and high pressure its cautious use is recommended, to decrease the pressure in the diseased vessel; and it may prove a valuable adjunct to rest and other means of treatment. The production of vomiting should be avoided and the patient should therefore be kept in a strictly recumbent position, while a small amount of opium may be given with the remedy. The action of veratrum viride is regarded as similar to a depletion, but without the permanent loss of blood, and on account of its influence in causing depression it has been designated as "the younger brother of tartar emetic."

The very marked efficiency of the drug (especially in the form of Norwood's tincture, see p. 142) in puerperal eclampsia, although this is a toxæmia associated with pregnancy, has been attested by trustworthy evidence, and by many physicians it is considered by far the best remedy at command in this condition. Its good effects have generally been attributed mainly to the depressing influence of the drug upon the motor tracts of the spinal cord; but, while this influence no doubt contributes in some measure to the beneficial

results, its action must be regarded as due to a very considerable extent to its action on the circulatory system. Since this remedy is not a vaso-dilator, the lowering of blood-pressure would likely be favored if nitroglycerin should be combined with it. In puerperal convulsions the spasmodic condition is generally, although not always, associated with abnormally high intra-vascular tension, and veratrum viride would consequently seem to be especially indicated. In this affection it has been pointed out that it possesses the double recommendation—(1) that it affords a certain and rapid means of lowering the blood-pressure; (2) that although it is not,cumulative to any marked degree, its action is long maintained, and may be perpetuated by a repetition of small doses. Sometimes, however, quite large doses are well borne, and successful instances of its use have been reported where as much as 1.20 mils (20 m) of Norwood's tincture has been given every hour for five consecutive days and nights. Here also the patient must be kept in an absolutely horizontal position in order to avoid the results of its depressing action on the heart.

In febrile conditions, although the action of veratrum viride differs from that of aconite chiefly in degree rather than in kind, the latter should be preferred. The nausea and vomiting, which veratrum viride so readily induces, is objectionable and should be avoided so far as is possible. A fall of temperature due to or accompanied by collapse is not desirable in any condition and drugs acting in this way are to be used with discretion, if at all, for this purpose. Notwithstanding the criticisms of those who regard it as a type of those cardiac sedatives which tend, it is claimed, to retain in the blood all that is injurious in it and at the same time to reduce the patient to a state of utter wretchedness, veratrum viride undoubtedly has a legitimate, though limited, field in therapeutics.

TOXICOLOGY

Notwithstanding the severity of the symptoms caused by it, and although it has often been given with great freedom, fatal results have seldom been noted from the use of veratrum viride. This is probably explained, at least to a considerable extent, by its prompt ejection from the stomach in consequence of the emesis produced by large doses taken by the mouth. Most of the symptoms of poisoning having already been given, the following only are mentioned. There is often very severe abdominal pain, and headache and giddiness are common.

There may or may not be muscular twitchings. After veratrine especially the convulsive movements are sometimes very marked. There is extreme debility, the features are pinched, and there is usually great pallor, with a cold and clammy skin. The medullary and spinal centers become paralyzed, and death results from respiratory collapse, adjuvated by failure of the circulation. The post-mortem changes are not characteristic.

Treatment. The treatment is practically the same as in aconite poisoning (see p. 460) although the contents of the stomach are usually efficiently evacuated by the action of the drug itself. Atropine has proved of some value in the poisoning of animals by veratrine, and its use is suggested on account of its action on the respiratory center and on the vagus terminations in the heart. As the poison is rapidly excreted through the urine it has also been recommended to administer hot tea as a diuretic.

DIVISION IV.-DRUGS ACTING ON THE VESSELS

These effects are usually determined (1) by direct observation of alterations caused by the drug in the size of the vessels of some thin structure, such as the ear of the rabbit, the wing of the bat, or the web, lung, mesentery, tongue or mylo-hyoid muscle of the frog; (2) by observing the rate at which the blood flows from the cut vessel of an animal, both under and without the influence of the drug. In order to exclude influences acting on the cardiac mechanism, the maintenance of an artificial circulation is quite commonly resorted to, and destruction of the spinal cord or section of the nerves supplying the part is required to determine whether the changes observed are due to local or central effects. When alterations in the vessels result from the local application of a drug it is often uncertain, if the nerves supplying the part are not divided, whether the effect is reflex or direct. It is probable that some of the drugs act by the vaso-constrictor and some by the vaso-dilator nerves, both of which connect the vessels with the central nervous system; but they can only be classified generally into those drugs which dilate or constrict the vessels by local action and those which do so through their action on the central nervous system. In those acting locally it is impossible to determine whether they affect the muscular coat of the vessel or the nerve terminations. It can readily be seen that drugs. which act on the heart or on a large area will have a considerable

effect upon the general blood-pressure. Drugs are applied to the interior of vessels by injecting them into the circulation.

A. Drugs acting locally on Vessels.

1. Vaso-dilators.

a. Drugs which, when locally applied to vessels, dilate them:

Irritants. Since they dilate the vessels, these drugs are often spoken of as vascular irritants. Warmth, if transiently applied dilates, but if for a long time, contracts blood-vessels.

Rubefacients. These are drugs which, in consequence of the vascular dilatation caused by them, redden the skin when they are applied to it. Desquamation frequently follows if the action has continued for some time. All the above are rubefacients.

Vesicants. With many of these drugs the irritant effect is sufficient to produce inflammation, and when they cause the exudation of serum between the epidermis and the true skin and the formation of vesicles or blisters they are known as vesicants; e.g., cantharides. Pustulants. These are drugs which produce small discrete suppurations, the distinct and separate points of inflammation being situated at the orifices of the skin glands. They do not affect the intervening tissue, probably for this reason that they cannot pass through the horny epidermis; e.g., croton oil.

Escharotics. With the most powerful of these drugs the irritation is sufficient to destroy the vitality of the tissues with which they came in contact, forming a slough, and to cause vascular dilatation in the surrounding parts. They are known also as caustics; e.g., zinc chloride.

Counter-irritants.-When any of these drugs are employed to produce a reflex influence on a part more or less remote from the point of application, they are termed counter-irritants. The exact nature of the effects of counter-irritation on internal organs has not been determined, but it is considered most probable that an alteration in the caliber of the vessels and in the sensory nerves or their terminations is induced, and that such changes may cause or be accompanied by a distinct alteration in the activity of the organs

b. Drugs which, when inhaled, by acting locally, dilate peripheral vessels: (1) Amyl nitrite. (3) Sodium nitrite. (4) Spirit of nitrous ether.

(2) Nitroglycerin.

c. Drugs which, when taken by the mouth, by acting locally, dilate peripheral vessels:

(1) Amyl nitrite.

(2) Nitroglycerin.

(3) Sodium nitrite.

(4) Spirit of nitrous ether.

(5) Belladonna.

(6) Hyoscyamus.

(7) Stramonium.

From a medical standpoint these are the most important of the vaso-dilators. 2. Vaso-constrictors.

a. Drugs which, when locally applied to vessels, constrict them:

These may act in two ways: (1) By contracting the muscular coat of the vessels; and (2) by coagulating the albuminous fluids around them, the coagulum, by its contraction, constricting the vessels.

Those which act on the muscular coat of the vessels:

Cold, temporarily applied, contracts, but when long continued, dilates bloodvessels.

Those which coagulate the albuminous fluids around the vessels:

(1) Tannic acid and all substances

containing it: e.g., nutgall, kino,

cinnamon, and gambir.

(2) Lead salts.

(3) Silver salts.

(4) Zinc salts.

(5) Copper salts.

(6) Alum.

(7) Ferric salts.

(8) Bismuth salts (slightly).

Astringents. These are drugs which diminish the size of the vessels, and thus decrease the amount of exudation from them. They