relaxing results. He should be instructed to dissolve a 100 grain tablet under his tongue, and repeat it every half hour until he obtains relief.

When it is decided to lower blood-pressure with nitroglycerin the choice is generally nitroglycerin or erythrol tetranitrate tablets. The frequency of the dose depends upon the effect on the individual, but generally four times in twenty-four hours is sufficient, a tablet after each meal and on going to bed. For this vaso-dilating effect the tablet should not be dissolved in the mouth, but should always be taken with plenty of water, and preferably when something is in the stomach. In other words, rapid action is not desired, and the disagreeable pressure feelings in the head need not be caused.

Symptoms of high pressure such as dizziness, a feeling of tension in the head, occipital headache, and cardiac ache, and possibly cold hands and feet, may be relieved many times by a small dose of nitroglycerin, as 1400 to 1500 grain, when a larger dose, as 1200 grain may cause headache; but the dose depends on the individual. It is rarely necessary, however, to give more than 100 of a grain, although that dose may be needed every three or four hours.

As stated under the subject of alcohol, in high fever, when apparently alcohol is indicated, nitroglycerin may act as well to dilate the peripheral blood-vessels and promote perspiration.

In spasmodic conditions such as occur in dysmenorrhea, at times vaso-dilatation from nitroglycerin may cause relief.

In insomnia from high pressure a dose of nitroglycerin taken with a cup of malted milk at bedtime will often promote sleep.

In attacks of asthma nitroglycerin will generally cause immediate relief. If the blood-pressure is low, however, and there is venous congestion and cardiac weakness, epinephrine on the tongue will often act more satisfactorily.

CLASS V

DRUGS USED FOR ACTION ON THE CENTRAL NERVOUS SYSTEM

This class includes drugs which have a very slight effect on the brain and spinal cord and drugs that have a profound effect

on the central nervous system, as anesthetics. Their action can only well be discussed in their separate sub-classes.

DRUGS USED TO STIMULATE THE BRAIN AND SPINAL CORD

The once called "antispasmodics" are drugs that seem to modify hyper-excitability and prevent various pseudo-spasmodic conditions and relax pain. These drugs are not narcotics, but cause improvement by stimulating the higher brain centers of control, actually as by camphor perhaps, or suggestively as by the disagreeable odor of the long used asafetida and valerian. These last named drugs may aid nervous control in hysteria by the psychic effect of the smell, or if in alcoholic preparations, may cause sufficient alcoholic cerebral effect to quiet the patient. Spirit of lavender has been much lauded for hysteria, but it is the alcohol only that is effective.

These drugs, namely, asafetida, valerian and lavender, at times so valuable in hysteria, are often less effective than is socalled "Christian Science."

Camphor is really a cerebral stimulant and dilates the peripheral blood-vessels, and may change the view-point of the hysteric. However, before hysteria is diagnosed as an entity in a given case, all other more tangible conditions must be excluded. There is generally a cause for these disturbed impulses, often an endocrine gland dysfunction. The thyroid gland is the one most generally in trouble, and frequently the ovarian function is abnormal.

Thyroid gland extracts are cerebral stimulants, especially in conditions that need such stimulation. The value of caffeine and atropine as circulatory stimulants has been discussed. They are also cerebral stimulants, the caffeine especially stimulating brain activity, and atropine especially stimulating the medullary centers and in large doses causing cerebral excitement. Strychnine is not only a medullary stimulant, but is especially a spinal motor stimulant. The discussion of the use of these drugs, caffeine, atropine, and strychnine as nervous stimulants would take us into the discussion of the treatment of shock, coma, and paralysis. Suffice it to say under this caption that none of these drugs should be used in nervous

irritability or in sleeplessness, and that coffee and tea are often the cause of insomnia.

Belladonna.-Belladonna is official both as the leaves and the root, but as all activities of belladonna are those of atropine, as far as its therapeutic use is concerned, there is no need for the preparations of this drug for internal use; we do not need the extract, the tincture, or the fluidextract of belladonna. The official belladonna plaster which represents 20 per cent. of the drug, and the official ointment of belladonna which represents 10 per cent. of the drug are useful preparations for external use. The official liniment of belladonna is superfluous, as the absorption of atropine could not be limited and poisoning might be caused.

The only use for belladonna externally is as a sedative to relieve pain and irritation. In susceptible individuals, even the belladonna plaster may cause poisoning, and the belladonna ointment should, also, not be used in a large amount at any one time.

Hyoscyamus.-There seems to be no good reason why this drug should be used as such or in its three official preparations. The tincture of hyoscyamus has been long used as a sedative, more especially in irritable conditions of the bladder, and in pelvic disturbances. There is no proof that there is an activity of this drug other than that of atropine. Its atropine-like alkaloid is termed hyoscyamine, but this alkaloid, unlike atropine, when used alone is likely to cause secondary depression. The other alkaloid of hyoscyamus, scopolamine (hyoscine) besides having a primary atropine action has a sedative action on the central nervous system; this alkaloid is used only as a hypnotic.

Hyoscyamine is official as Hyoscyamine Hydrobromidum, but as this drug is likely to cause unexpected depression, there seems to be no justification for its use.

Scopolamine Hydrobromidum (hyoscine hydrobromide) is very soluble in water, and is used principally hypodermatically in intense cerebral excitement, in acute delirium, and in the sleeplessness of insanity. When given hypodermatically, or in a tablet to be dissolved in the mouth, it generally quickly causes sleep. However, when there is an idiosyncrasy to

atropines, it may cause considerable cerebral excitement. Consequently, before giving a full dose of this drug, it should be ascertained that the patient is not susceptible to atropine. After a sleep from scopolamine there is likely to be considerable circulatory depression. Consequently, it is not wise to give scopolamine as a hypnotic and then allow the patient to be up and about the next morning.

Scopolamine has also been used in spinal irritability, and in paralysis agitans. The dose for these purposes is smaller, not sufficient to produce sleep, and it should be administered two or three times a day. In such patients a tolerance has sometimes been developed, and larger doses may be needed.

Although scopolamine may cause atropine stimulation, it should never be considered that it is anything but a depressant, and when serious poisoning occurs, depression must be combated.

The average dose is 0.0003 Gm. (200 grain). It is often necessary, however, to give double this dose, 100 of a grain. Stramonium is official as the leaves. The action of this drug is only that of atropine, and therefore there is no good excuse for its four official preparations. The action and poisoning of stramonium is that of an atropine.

The only use for stramonium is in the form of the leaves, to be made into cigarettes or pastilles, or to be burned as a powder, for inhalation in asthma. Generally the leaves are combined with nitrate of potassium (saltpetre) which causes the drug to burn rapidly, and also gives some relaxation from the nitrite formed when the fumes are inhaled. The action of stramonium when inhaled is that of a sedative from the action of the atropine on the nerves of the mucous membrane of the air passages. Although inhaling this fume of atropine may give local sedative action to irritated nerve terminals in the region that is spasmodically contracted, still atropine sulphate given hypodermatically or dissolved in the mouth may cause the same satisfactory effect.

Atropine.-Administration.-This drug is best used in the form of the official sulphate, which occurs as a white powder, very soluble in water. The dose varies from 0.0003 to 0.0006

Gm. (200 to 100 grain). In particular conditions, for specific purposes, much larger doses may be given. Although more or less rapidly absorbed, the full effects of the drug do not occur until after several hours, the length of time of course depending upon the mode of administration. Also the drug is slow of excretion and its action is therefore prolonged, hence atropine for any purpose should not be frequently repeated, rarely more than once in six hours, and then only for a few doses, unless the dose administered is very small.

Action.-Atropine more or less inhibits all secretions, and therefore may tend to inhibit the gastric secretion, and for this reason has been used much for hyperacidity. For this purpose, however, its use is not a success. It dulls the peripheral endings of the nerves and therefore decreases intestinal irritability, and for this purpose it is often combined with laxatives with the object of preventing bowel cramps.

After absorption it dries all secretions, especially those of the nose, throat, mouth, and bronchial tubes. It also decreases perspiration. It is a most active stimulant to the respiratory center, more or less accelerates the pulse, somewhat raises the blood-pressure by stimulation of the vasomotor center, and somewhat constricts the blood-vessels of the splanchnic region. At the same time it causes dilatation of some of the surface vessels, more especially of the face and the upper part of the body, and hence often causes flushing, and even a scarlatiniform eruption.

If applied locally to the eyes, or if absorbed in any considerable amount, it causes dilatation of the pupils, and when applied locally to the eye in strong solutions (the strength most used for this purpose being 1 per cent.) it causes paralysis of accommodation. Atropine may be more or less absorbed from the skin and cause dulling of the peripheral nerves and cessation of peripheral pain. It is excreted mostly in the urine, and perhaps may be excreted in the milk of nursing women.

Over-action. More individuals are susceptible to, and show an diosyncrasy against, atropine in any form than to any other one drug; some individuals, have an excessive action from the drug even from small doses. Besides the scarlatiniform