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as the Aromatics, Volatile Oils, Vegetable Bitters, Mineral Acids, Nux Vomica, Mustard, Capsicum, etc. Hepatic Stimulants, as Nitro-muriatic and Nitric Acids, and the cholagogue purgatives, Podophyllum, Jalap, Leptandra, Euonymin, Iridin, etc. Intestinal Stimulants, as Mercurials, Elaterium, Colocynth, Jalap, Scammony, Podophyllum, etc., which affect the glandular apparatus,-and Belladonna, Physostigma, Nux Vomica, Rhubarb, Senna, Aloes, Frangula, Cascara, etc., which chiefly affect the muscular fibres and the intestinal nerves. Cutaneous Stimulants, as the diaphoretic group, and the rubefacients, Mustard, Capsicum, Turpentine, Ammonia, etc. All stimulation reacts into depression, and most of the agents which stimulate the nerve centres at first soon depress and finally paralyze them.
Sedatives (Sedo, I allay), -are agents which exert a soothing influence on the system by lessening functional activity, depressing motility, and diminishing pain.
General Sedatives include the narcotics and anaesthetics. Local Sedatives include Aconite, Opium, Ice, etc. Pulmonary Sedatives, as Hydrocyanic Acid, Veratrine, and the nauseants and emetics. Spinal Sedatives, as Physostigma, Gelsemium, Potassium Bromide. Stomachic Sedatives include Arsenic, Bismuth, Nitrate of Silver, Bicarbonate of Sodium. Vascular Sedatives, as Digitalis, Tobacco, Aconite, Veratrum, and the emetics. Nervous Sedatives, among which are Potassium Bromide, Tobacco, Lobelia, and the group of spinal depressants.
AGENTS ACTING CHIEFLY ON THE NERVOUS SYSTEM.
Motor-Excitants are agents which increase the functional activity of the spinal cord and the motor apparatus, producing disturbances of motility, heightened reflex excitability, and tetanic convulsions when given in large doses, their ultimate effect being motor paralysis from overstimulation.
The most important members of this class are Nux Vomica and Ignatia, with their alkaloids Strychnine and Brucine, also Thebaine, the tetanizing alkaloid of Opium. It also includes Morphine and Atropine, which, though at first sedative, when given in large doses produce convulsions. The respiratory centre in the medulla is stimulated by Strychnine, Atropine, Ammonia, and small doses of Alcohol, Ether, and Chloroform. The motor convolutions in the brain are stimulated by Alcohol in moderate doses, as also for a brief period by Ether and Chloroform.
The end-organs of the motor nerves are stimulated by the local use of Electricity, Strychnine, and friction; and are irritated by the internal administration of Aconitine, Nicotine, Camphor, Pilocarpine, and Pyridine. Other members of this class are embraced in the following list :
Motor-Depressants lower the functional activity of the spinal cord and motor apparatus, and in large doses paralyze them. Some act indirectly by reducing the spinal circulation, as Digitalis, Aconite, and large
* In large doses.
In small doses.
doses of Quinine; others by a directly paralyzant action on the centres. The principal members of this class may be enumerated as follows, viz.:
Ergot (at last).
The motor centres in the medulla are powerfully depressed by Opium, Morphine, Aconite, Conium, Chloral, Physostigma, and large doses of Alcohol, Ether, and Chloroform. The three last named are also paralyzers of the motor convolutions in the brain, arresting all voluntary movements when administered in sufficient quantity. The anterior cornua of the cord are greatly depressed by Physostigma and other agents, and the motor nerves by Conium, Methyl-Strychnine, etc., both actions resulting in paralysis of the limbs. Curare, even in small doses, paralyzes the end-organs of the motor nerves, and Belladonna, the compound Ammonias, Methyl compounds, etc., exercise a similar but less powerful influence. Galvanism is also an effective local depressant of motor activity.
Local Stimulants increase common sensibility to the extent of producing pain, chiefly by direct action upon the end-organs of the sensory nerves in the skin, though some act probably by stimulating the local circulation, as in inflammation. The principal members of this group
Other Methyl Compounds.
Ethyl Ammonium Chloride.
* In large doses.
Local Anæsthetics and Anodynes (an, without, aistheysis, percep tion, odunay, pain),-reduce the functions of the sensory nerves until they lose the power of receiving or conducting sensations. Some act by direct depression of the end-organs in the skin, etc., others by impairing the conductivity of the sensory nerves, while some act indirectly by reducing the local circulation. The Anodynes diminish, and the Anæsthetics destroy, for a time, the sensibility of the skin or mucous membrane. The chief agents of this class are
Acrid Essential Oils.
Veratrine (at first).
Cerebral Excitants,—are remedies which increase the functional activity of the cerebrum, without producing any subsequent depression, or any suspension of the cerebral functions. They act partly by increasing. the action of the heart and consequently the rapidity of the circulation, partly by a direct action upon the gray matter of the brain. The chief members of this group are
Alcohol (at first).
Oil of Turpentine.
Acetic Acid (inhaled).
Deliriants excite the functions of the higher brain to such a degree as to disorder the mental faculties, producing intellectual confusion, loss of will-power, delirium and even convulsions. They are all narcotics (though all narcotics are not deliriants), and may be listed as follows, viz.
Lupulus (at first).
Cerebral Depressants lower or suspend the functions of the higher cerebrum after a preliminary stage of excitement. Under this head may be included the Narcotics, General Anæsthetics, and several of the Antispasmodics, all acting on the cells of the convolutions, at first stimulating the brain functions, they produce after a time stupor, coma and insensibility.
The most useful of this class are the Bromides, Zinc and Caffeine, as they also diminish reflex excitability and thus secure rest of the nervous system. Some of them are decidedly dangerous, as they may paralyze the heart or the medulla and its centres of organic life before the consciousness is much disturbed; such being Chloroform, Aconite, Opium, and the irritant poisons.
Narcotics (narkay, stupor), are agents which, at first excitant to the higher brain, produce profound sleep, characterized by stupor, and if the dose be sufficient, coma, insensibility and death by paralysis of the medullary centres governing respiration and other functions of organic life. They are closely related to stimulants, Opium and Alcohol being
good illustrations, in the different stages of their action, of both stimulant and narcotic effects. They give us the power of lowering perception, inducing sleep and soothing the vital functions by rest, all of which are means of great therapeutical value. The chief narcotics are
Hypnotics (heupnos, sleep),—are remedies which produce sleep, and in this wide sense of the term the class would include the Narcotics and the Anæsthetics, as well as those agents which may be termed Pure Hypnotics, which induce sleep by bringing the brain into a favorable condition therefor, rather than by direct soporific action. In this sense the purest hypnotics are the Bromides, but artificial sleep may be produced by many other agents. The principal members of this class are the following:
Opium, Morphine, Narceine.
Chloroform, Ether, etc.
Analgesics (an, without, algos, pain), or Anodynes (an, without, odunay, pain),-are remedies which relieve pain either by direct depression of the centres of perception and sensation in the cerebrum, or by impairing the conductivity of the sensory nerve fibres. Opium is the most efficient of all analgesics, because it arrests the afferent impressions at every step of their track-at their formation, along the course of their conduction, and at the point where they impinge on the sensorium. The Local Anodynes have been described, and the list of General Anodynes includes the following-named agents, viz.
Chloroform, Ether, etc.
Anæsthetics (an, without, aisthaysis, perception),-are agents which destroy sensation. Local Anaesthetics have been described. General Anesthetics are certain volatile substances, mostly belonging to the class
of alcohols and ethers, which when inhaled produce complete unconsciousness and loss of sensation (anesthesia), with lessened motor power.
Narcotics also produce anæsthesia, but the term is usually restricted to the effects of the volatile agents referred to. The principal members of this group are
Ether (Oxide of Ethyl).
Bichloride of Methylene.
Antispasmodics (anti, against spasmos, a spasın),-are agents which prevent or allay spasm of voluntary or involuntary muscles in any portion of the organism. Some of the agents belonging to this class act by stimulation of the higher nervous centres, the coördinating power, and the circulation, as Alcohol and Ether in small doses, Camphor, Musk, Valerian, etc.; others by a depressant influence on the motor centres, as the Bromides; and still others by paralysis of the end organs of the vasomotor nerves, as Amyl Nitrite. A few depress all the vital functions, as Aconite, Tobacco, Lobelia, Hellebore, and Prussic Acid; and a long list stimulate the bowels to expel gaseous accumulations, namely, Asafetida, Cajuput, Valerian, Musk, Aromatic Oils, etc. They are used in convulsive affections, especially asthma and other spasmodic diseases of the respiratory organs, hysteria, chorea, angina pectoris, epilepsy, etc. The principal antispasmodics are as follows, viz.
The Cerebellum is affected by a few drugs, their action upon its several lobes producing various disturbances of equilibrium.
Alcohol is the principal agent acting upon this portion of the brain, and different products of the still seem to affect different portions of the cerebellum. For instance, intoxication by wine or beer is said to cause lateral falling, that by whiskey an inclination to fall face downwards, cider a backward tendency (Brunton). Apomorphine in large doses produces a tendency to move in a circle, and therefore probably affects the cerebellum or the corpora quadrigemina.
AGENTS ACTING ON THE ORGANS OF SPECIAL SENSE.
Mydriatics (meudos, moisture),—are agents which produce dilatation of the pupil of the eye (mydriasis). Some act locally, others when given internally, and the principal ones (Atropine and its congeners) act both locally and internally, producing at the same time paralysis of the ciliary