This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
C4H10O, or "(C2H5)2O. Sp. gr. - Of pure ether, 0.713; of stronger ether, 0.728; of ordinary officinal ether, 0.750.
Sulphuric Ether is obtained by the distillation of alcohol and sulphuric acid, and is rectified by re-distillation with solution of potassa. The form of sulphuric ether employed for inhalation is still further purified by agitation with water, and it is freed from this and from an excess of alcohol and deleterious acid substances by the action of chloride of lime and freshly calcined lime, when it is known as stronger ether - AEther Fortior. Pure ether has a Sp. gr., 0.713, and is practically free from alcohol and water. Sulphuric ether is a colorless, limpid, volatile and inflammable fluid, with a sweet, penetrating odor and a hot, pungent taste; on account of its great volatility, it should be kept securely in ground-glass-stoppered bottles. It should never be held near a fire or light. It usually reddens litmus paper slightly; when it does so strongly, the ether is impure. The impurities, besides acids and fixed substances, are heavy oil of wine, an excess of alcohol and water. Acids being detected by litmus paper, may be removed by agitation with potassa; fixed substances may be removed by evaporating the ether. Some alcohol is always found in ether, and it is only when it is present in too great a quantity that the density of the ether is rendered too high. The quantity of alcohol any preparation of ether may contain, can be determined by agitating it in a minim measure with half its volume of a concentrated solution of chloride of calcium. This will remove the alcohol, and the reduction of the volume of ether when it rises to the surface will indicate the amount of alcohol which has been present. Heavy oil of wine can be detected by the ether becoming milky when mixed with water. Ether boils at 950 E., and a cold of 166° below zero will not freeze it. When kept too long it undergoes decomposition, and is converted in part into acetic acid.
It evaporates so readily and completely in the air as to cause a great degree of cold; hence it has been employed in the form of spray, as a local anaesthetic. It combines with alcohol and chloroform in all proportions, and dissolves in ten times its volume of water.
Ether is a diffusible stimulant, antispasmodic, anodyne and anaesthetic. Its action on the animal organism is rapid and powerful, but temporary, and, except for its rapidity, is similar to that of alcohol. When applied to the skin it produces intense cold by its evaporation, and when applied in the form of spray it benumbs or locally freezes a part.
Both the liquid and vapor act as an irritant to mucous membranes, and its vapor when first inhaled causes great irritation of the fauces and respiratory tract, often causing a temporary arrest of respiration, the face becoming suffused and red and the conjunctiva injected, such conditions causing restlessness and struggling; but a quiet stage soon follows the primary stage. During this second stage, the breathing is usually full and deep, and the pulse rapid and strong, the ocular reflexes at the beginning being intact. The second stage may also be one of struggling, during which the patient may become uncontrollable except by great force, but if the inhalation be pushed a third stage of complete anaesthesia is soon attained, when any surgical operation may be performed. The inhalation should not be carried to complete flaccidity of muscular contraction as the respiration may be obstructed.
Sulphuric ether first acts upon thebrain, then upon the sensory and motor tracts of the spinal cord, then on the sensory and motor tracts of the medulla oblongata, and, if given to excess it causes death from respiratory failure. It produces no effect upon the nerve trunks unless it is directly applied to them. It does not act by any destructive influence on the blood, but simply suspends for a time the vital functions of the part which it effects. It is one of the most diffusible and rapid cardiac stimulants, increasing the pulse rate and force, and stimulating the heart and the arterial pressure by accelerating the activity of vaso-motor centres. In excessive doses it is a depressant of the heart, and decreases the haemoglobin and the number of the red corpuscles, especially in the anaemic. It acts as a powerful stimulant on the respiratory centre, but in excessive doses it paralyzes this portion of the system. It lowers the bodily temperature by depressing the nervous system, and by its evaporation. It is eliminated by the lungs and kidneys. It is administered internally in the form of ether or of Hoffmann's Anodyne, compound spirit of ether - Spiritus Etheris Compositus (composed of ether, Oss, ethereal oil, and alcohol, Oj), also, in the form of spirit of nitrous ether, Spiritus Etheris Nitrosi, and known as sweet spirit of nitre (a solution of nitrous ether in alcohol). Ether is internally given in ice-cold water or capsule.
When ether is taken into the stomach, it causes a cooling sensation, after the subsidence of the burning, which is quickly diffused over the body; increased action of the heart, flushing of face and warmth of surface follow in a few minutes; the senses are quickly excited; the mind becomes more active, and the phenomena of alcoholic intoxication result, which soon pass away, leaving a feeling of calmness and sleep.
Ether is employed internally as an antispasmodic and anodyne, for angina pectoris, hysteria, asthma, flatulence, cramp of stomach and bowels, syncope, epilepsy, hiccough, nervous or hysterical headache. Hoffmann's Anodyne possesses the antispasmodic and stimulating effects of ether, and the anodyne effects of ethereal oil, or oil of wine, and is also carminative. Ether vapor should not be administered in bronchitis or acute kidney disease on account of its irritant effects, nor in aneurism, peritonitis or gastritis.
Of ether, to of Hoffmann's Anodyne, to in sweetened water ; of spirit of nitrous ether, to
Ether is employed as a general and local anaesthetic; as a topical anodyne in neuralgia and odontalgia, for which purpose it is generally combined with other agents; in aphthae and stomatitis; as a counter-irritant, evaporation being prevented; also in saturated solutions with other agents.