sive sublimate (1 to 8000 or even weaker) or the application of carbolic acid in glycerin. Internally it is a gastro-intestinal irritant, causing also drowsiness, stupor, delirium and convulsions. Its precise use is not clear, but it has been given as a substitute for nux vomica in paralysis and in incontinence of urine. Dose gr. j-iij (0.06-0.19), perhaps, if given at all; best administered in the form of a tincture.

PICROTOXINUM-PICROTOXIN.

What is picrotoxin?

Picrotoxin is a neutral principle prepared from the seeds of Anamirta paniculata (Nat. Ord. Menispermacea), a climbing shrub of India. Its action on the brain resembles that of belladonna, while it affects the spinal centres somewhat like nux vomica: thus, it causes nausea, vertigo, delirium, incoördination, muscular twitching, followed by epileptiform convulsions, alternating tonic and clonic spasms, coma and cardiac paralysis. It stimulates all the motor and inhibitory centres of the medulla, particularly the respiratory and vagus centres, and excites the motor and reflex spinal centres. It is at present chiefly used to check the night-sweats of phthisis, but has also been recommended as an excito-motor in functional paralysis and in paralysis or relaxation of the sphincters. It is said to be of service in chorea when given in full doses. Locally it is used as an ointment (gr. v-x to 3j (0.3-0.6 to 31.0)) in parasitic skin diseases and to destroy pediculi, but care should be used in applying it, as constitutional effects and even death have followed its employment externally. Dose gr. 200-8 (0.0003-0.001).

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ORDER VI.-DEPRESSO-MOTORS.

What are depresso-motors?

They are remedies which are used to depress the functions of the spinal cord, motor nerves or muscles, thus lessening motivity.

Name the members of this group.

Physostigma; chloral; the bromides; the nitrites; gelsemium; prussic acid; the cyanides; oil of bitter almonds; lobelia ; conium; woorara, and tobacco.

PHYSOSTIGMA.

What is physostigma, and what active principles does it contain?

Physostigma, or Calabar bean, is the seed of P. venenosum (Nat. Ord. Leguminosa), a plant found on the western coast of Africa. It contains an alkaloid called eserine or physostigmine, and it is claimed that a second alkaloid (a tetanizing agent), called calabarine, has also been discovered, but this is probably a derivative-alkaloid of eserine.

What are the physiological effects of physostigma ?

Calabar bean is a reflex depressant, causing also, in full doses, giddiness, slow and often irregular pulse, great muscular weakness, nausea and sometimes vomiting, generally free purgation, and usually contraction of the pupils. When poisonous doses are taken, there are, in addition, muscular tremors and abolition of reflex action, slow pulse and respiration, myosis and motor paralysis, and death from respiratory failure.

It depresses and finally paralyzes tne reflex and motor centres of the spinal cord, having but slight effect upon the nerves themselves. It slows the heart (by greatly lengthening the diastolic pause) and increases its power (acting either on the cardiac motor-ganglia or muscle). The blood pressure at first falls, but soon rises and remains high until death approaches. It stimulates intestinal peristalsis and increases the secretions of the part. On the eye its action is probably directly opposed to that of atropine, for no matter how used it contracts the pupil, probably by paralyzing the peripheral sympathetic nerve-fibres in the iris and at the same time stimulating the end organs of the 3d pair of nerves. It is probably eliminated by the urine.

How should poisoning by this drug be treated?

(1) Give emetics and cathartics, and use a catheter to prevent further absorption of poison; (2) use atropine hypodermically as a physiological antagonist, and (3) give other cardiac and respiratory stimulants as digitalis, ammonia, and alcohol.

For what purpose is it employed medicinally?

As a depresso-motor it is used in tetanus, trismus neonatorum, epilepsy and chorea with some success. It has also been given as a

physiological antagonist in strychnine poisoning, but is probably inferior to chloral for this purpose.

From its influence over intestinal peristalsis, it is advantageously used in habitual constipation, especially when associated with chronic intestinal dyspepsia and dry, hard stools. The alkaloid is used in ocular therapeutics, to prevent or overcome adhesions of the iris, lessen intra-ocular tension and contract the pupil.

What are its preparations and doses?

EXTRACTUM PHYSOSTIGMATIS (extract of physostigma), dose gr. (0.005-0.03).

TINCTURA PHYSOSTIGMATIS (tincture of physostigma), dose mvxxx (0.3-2.0).

PHYSOSTIGMINÆ SULPHAS (physostigmine sulphate), a very deliquescent salt; dose 6-12 (0.001-0.005).

PHYSOSTIGMINÆ SALICYLAS (physostigmine salicylate), preferred to the sulphate because of its greater permanency; dose gr. 6-12 (0.001-0.005).

CHLORAL and THE BROMIDES have been discussed under the head of hypnotics (vid. pp. 95-99).

What are the nitrites?

THE NITRITES.

The nitrites are salts formed by the union of nitrous acid* with a base.

Amyl nitris (amyl nitrite) is the only official organic nitrite (except the sweet spirits of nitre, which contains ethyl nitrite and will be considered elsewhere). It is a yellowish, oily, very volatile liquid, with a pleasant, fruity odor. Nitroglycerin (trinitrin, trininitroglycerin or glonoin) is a colorless, oily liquid, without odor, soluble in ether and alcohol. It forms the basis of various explosives. It is really a trinitrate (not a nitrite) of glyceryl or propenyl [C2H5(NO3)3]. Potassium and sodium nitrites are also used.

What is the physiological action of the nitrites?

They cause vertigo, headache, excited cardiac action, great dilata

See foot-note on p. 71.

tion of the arterioles and capillaries (from paralysis of their muscular coats), and consequently greatly diminished blood pressure, slowed respiration, lowered temperature, and diminished reflexes. After toxic doses, the pupils dilate, the muscular system relaxes, the blood becomes darker (probably from the formation of methemoglobin), the respiration and circulation become slow and irregular, and finally death occurs from respiratory failure, sensation and consciousness being preserved to the last. They depress both the motor and reflex spinal centres without influencing either the sensory nerves or centres. They first stimulate the heart, but soon depress and finally paralyze the cardiac muscle by direct action. The temperature is lowered, owing to lessened oxydation. The nitrites are all muscle poisons. They are eliminated by the urine, increasing greatly the amount of water and the uric acid and urea. The action of amyl nitrite is the most rapid, but most transient; nitroglycerin is the slowest, but its effects are more lasting,―the headache, however, which it causes, is very persistent, and often constitutes a great objection to its use. It sometimes causes nausea and vomiting.

What are the therapeutical uses of the nitrites?

The nitrites are used (1) as depresso-motors to relax spasm in angina pectoris, asthma, tetanus, puerperal and other forms of convulsions, strychnine poisoning, congestive and nervous dysmenorrhoea, and in all cases of very high arterial tension from spasm of the arterioles; thus, in renal asthma the inhalation of a few drops of amyl nitrite quickly relieves the spasm, and migraine with capillary spasm is frequently benefited by it. Given just before the expected chill of malarial fevers it will abort it, and sometimes avert the paroxysm. If amyl nitrite is inhaled when the " aura epileptica' is experienced, it will often prevent the epileptic attack. Nitroglycerin has proved of value in chronic interstitial nephritis, lessening the albuminuria and relieving the arterial spasm. Obstinate hic

cough has been benefited by nitroglycerin.

(2) As cardiac stimulants the nitrites are employed in syncope, cardiac dyspnoea, and in threatened cardiac failure during the administration of anaesthetics, especially chloroform.

(3) They have also been found useful in the nausea and vomiting of sea-sickness and of pregnancy.

What are the doses of the nitrites, and how are they administered?

AMYL NITRIS (amyl nitrite), given internally or by inhalation; dose mij-v (0.1-0.3).

SODII NITRIS (sodium nitrite), dose gr. ij-iij (0.1–0.2).

Potassium nitrite is not official. It may be used in the same doses as the sodium salt.

SPIRITUS GLONOINI (spirit of glonoin—spirit of nitroglycerin) is a 1 per cent. alcoholic solution of nitroglycerin, the dose of which is mss (0.03) cautiously increased.

Triturates of nitroglycerin, each containing gr. 1 (0.0006), are also employed.

Amyl nitrite is usually given by inhalation, but may be administered internally on sugar, or even hypodermically. The other preparations are given by the mouth. If a speedy action is required amyl nitrite should be used, and after the immediate danger is over, if it is desired to maintain the effect, the other nitrites or nitroglycerin may be given.

GELSEMIUM.

What is gelsemium, and what chemical principles does it contain ?

Gelsemium is the rhizome and roots of G. sempervirens, the yellow or Carolina jasmine (Nat. Ord. Loganiacea), a climbing plant of the Southern States. It contains two alkaloids, gelsemine and gelseminine, combined with gelseminic acid, a volatile oil, resin, etc.

What are its physiological effects?

Small doses produce languor, dizziness, and perhaps slight lowering of the pulse rate; large doses diminish the force and frequency of the pulse and lower arterial pressure, depress respiration, cause frontal headache, and disordered, usually double vision; toxic doses cause extreme muscular weakness, partial blindness, dilated pupil, often internal strabismus, ptosis, incoördination, the jaw drops, articulation is impaired, general sensibility is much diminished, respiration is slowed, the pulse is very feeble, the temperature declines, a profuse cold sweat breaks out, and death occurs from respiratory failure, preceded in animals by convulsions followed by