Etherum

[ETHYL OXIDE, ETHYLIC ETHtiE, SULPHUEIC ETHEE.]

Ether is a colorless liquid, of a very peculiar, though not un- pleasant odor, and of a pungent taste. It is very volatile, and is combustible. Its vapor, mixed with atmospheric air or oxygen is violently explosive. It is readily soluble in alcohol in any proportion; sparingly so in water and freezes at 46° below zero.

Its specific gravity is about 0.740. Ether is wholly an artificial product. It is prepared by heating in a glass retort equal portions of sulphuric acid and alcohol, well mixed by stirring. The vapors (formed are carried into a vessel, kept at a low temperature by the use of ice and upon condensing give ether.

Ether is of particular interest to us because of its anaesthetic properties. It does not act with the rapidity of chloroform, neither is its administration as pleasant, for it is apt to cause annoying fits of cough and to leave behind it severe and tedious headache ; but it can be administered with so much greater safety than chloroform, that many operators prefer it to chloroform and to other similar agents.

94 ETHEE.

The general narcosis of ether is caused by absorption into the blood. Carried into the fine ramifications of the arterial system, it produces its peculiar effects upon the nervous system, acting from the periphery to the center, paralysis taking place in the posterior extremities, and extending from there forward to the anterior extremities. The conjunctiva of the eye is the last structure which yields to its influence.

The study of the peculiar effects of ether, when administered with the intention of producing narcosis, is of great interest. I shall merely point out a few items of particular importance.

o3r. Anstie placed a middle-sized, full-grown and healthy rat into a glass jar of 1260 cubic inches capacity, containing ten grains of the vapor of ether to 100 cubic inches of air. The animal instantly became very much excited, and ran round the jar, leaping up as if to escape. In less than one minute it fell on its side ; the respira- tion was perceived to be extremely hurried ; the rat was, apparently, quite unconscious.

Several clonic convulsions of the limbs now occurred, after which they appeared to become rigid. Five minutes after its introduction to the jar, the animal was breathing only by isolated gasps. It was now removed to the outer air, one or two gasping respirations ensued, and respiration then ceased. The thorax was opened, and the heart was observed to beat for three and a half minutes longer.

An average-sized, full-grown, healthy white mouse was introduced into the same jar, charged with an ether vapor of the same strength as before. Instantly the animal gave one or two spasmodic leaps upward, and then fell on its side with rigid limbs and slight tremu- lous movements. In ninety seconds it was removed from the jar, and almost simultaneously the breathing ceased. The chest was immediately slit open, and the heart seen to be motionless, except for a slight pulsation of the auricles.

Irritation (by pricking) failed to set the ventricles in movement.

An healthy, active rat was introduced into the same jar, charged with ether vapor in proportion of two and a half grains to one hun- dred cubic inches of air. The animal ran round the jar in a very excited manner, and tried to leap up the sides of it. In seventy seconds it began to stagger and fall about as if drunk, and in less than two minutes it lay on its side. Being removed from the jar, however, it was found to be only partially unconscious : the hind quarters were quite insensitive, as likewise the muzzle ; the con- junctiva, however, and the skin of the chest and fore limbs were quite sensitive.

It recovered perfectly after five or six minutes exposure to the air.

A large, rough terrier, very active and in full health, had half an ounce of ether injected into his peritoneal cavity. The animal

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seemed frightened, but not particularly hurt, and when released Tan about the room, wagging his tail. -Three minutes after the injection the dog, which had been lying down for a few moments, got up and blundered across the room as if he had been drunk, and knocking himself against various objects. He now became highly excited, and, falling on his side, he began to snap at everything near him, and to knock his muzzle repeatedly on the stone floor. Placing him on his feet, I found that his hind-quarters were quite paralyzed as to voluntary power and sensation ; and, moreover, it was evident that the muzzle had lost all its sensibility. ' The dog did not cry nor otherwise give the slightest sign that he was in any pain ; it was obvious that the symptoms were those of partial ether-narcosis.

An apparatus was now adjusted to the animal's face, by means of which the air expired from the lungs was made to pass through a solution of one part bichromate of potash in 300 parts of strong sulphuric acid ; after three or four minutes had elapsed, the elimination of ether was demonstrated by the formation of the emerald-green oxide of chromium. From the decided effect produced on the test-solu- tion during the first few minutes it was obvious that the elimination was proceeding very rapidly; and pari passu with this process the symptoms of anaesthesia subsided.

In half an hour from the com- mencement of the test-process a very feeble reaction could alone be obtained, and correspondently with this it was observed that only a very slight degree of anaesthesia and muscular weakness of the hind limbs remained. No evil consequences whatever followed this rough treatment of the peritoneum.

A man of forty years of age, in sound health and of muscular build, inhaled ether before undergoing a minor operation of the eye. No voluntary struggling took place, and the vapor did not appear to irritate the air-passages. Eespiration, which at the commencement was 16 per minute, retained this rate during the whole of the first minute. The pulse (which at the commencement of inhalation was seventy -four) mounted "during that time to ninety-six, and was very forcible in its beat.

Sixty-five seconds from the first inspiration of ether the patient sat up and looked at me with a roguish leer for a moment or two. He then sank back and began to gabble incohe- rent nonsense with great fluency, and at first with perfect articula- tion : by the end of the second minute the pulse had risen to 104 ; respirations 18; the eye somewhat congested, the face of the natural tint, the pupil apparently unaffected in size and quite sensitive to changes of light. There was now very perceptible diminution in the sensibility of the skin of the hands ; there was also commencing rigidity of the muscles of the arms and fore-arms, and more decided stiffness of the legs.

At the end of the third minute articulation had become confused ; there was a copious flow of frothy saliva, which the patient made no effort to get rid of ; consciousness was apparently lost, mucular rigidity was general and very strong, par- ticularly in the muscles of the neck ; the face flushed and sweating,

96 ETHER.

the eyes very much congested, the pupil contracted and insensitive. Pulse 98 ; respiration 28. At this moment an attempt was made to explore the injured eye, but the lids closed with spasmodic firmness at the first touch on the conjunctiva of their edges. Inhalation was continued for two minutes longer ; at the end of this time mus- cular rigidity had disappeared, the patient was profoundly uncon- scious, the pupils dilated, and the conjunctiva was perfectly insensi- tive ; pulse 96; respiration 21, snoring.

The eye was now explored and the foreign body removed in less than a minute. The patient had completely regained consciousness at the end of seven minutes from the withdrawal of the ether inhaler; pulse 72; respiration 15. At tliis time, however, and for several minutes longer, there was still some feeling of numbness in the feet and in the calves of the legs, slight dizziness, and a slight deficiency in the co-ordination of the movements of the lower limbs in walking. On examining the in- haler, three ounces of ether were found to have been used.

A study of Dr. Anstie's experiments shows that ether-narcosis may be produced by inhalation and by absorption of the agent through the peritoneal surface ; the former method only is of practical in- terest to the physician. The effects of ether are produced, as already stated, by its absorption into the blood. In moderate doses from inhalation or injection the nervous system becomes more or less paralyzed, all the parts of the nervous system becoming equally in- volved.

In fatal doses death takes place by the effects of the agent upon the medulla oblongata, causing paralysis of the respiratory movements.

The pulse and the respiratory movements are increased from the commencement of inhalation, but drop below their normal beat and number when narcosis is fully developed. When excessive rapidity of circulation takes place, it indicates danger of approaching par- alysis of the sympathetic nervous system.

Flushing of the face with a tendency to perspire usually follow the increase of the pulse-beat ; an increase of the salivary secretion, disturbances in the perceptive faculties of the patient, and loss of motion with rigidity of the muscles develop next. These symptoms constitute the first stage of ether -narcosis, during which the pupil is usually contracted and the patient, although not very sensitive to slight hurts, still retains consciousness. If inhalation is continued, the next stage of narcosis develops, characterized by relaxation of the muscular apparatus, depressed state of circulation and respira- tion, dilatation of the pupils and profound unconsciousness. If the administration of the anaesthetic is now discontinued, consciousness

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will return in a short time, (from thirty seconds to seven or ten minutes) and the patient recovers his usual state of health, with the probable exception of an headache and some disturbance in the nervous system, such as numbness in the extremities and deficiency of co-ordination in the lower limbs.

Your especial attention is called to the experiment which shows the elimination of ether by the lungs.

The production of diabetic symptoms, as a feature of ether-nar- cosis, has been amply demonstrated and is generally recognized. So far, no satisfactory or conclusive explanation of the phenomena has been given

In cases, wheue dangerous symptoms develop during the adminis- tration of ether, we must rely upon the establishment of artificial respiration.

It may be well known to you, that the evaporation of ether, when poured upon the skin, produces a feeling of intense coldness. This has been utilized by the surgical world in the reduction of compli- cated hernia. A number of cases' are on record where skillful manipulation had been employed for a long time and unsuccessfully, threatening to make operative interference necessary. A drachm, or more, of ether poured directly upon the naked skin and permitted to evaporate, caused so remarkable a change, that replacement of the intestine was easily performed.

To the pharmaceutist ether is of some interest, because it dissolves phosphorus and a few other agents not readily soluble in alcohol ;. it is also used in the preparation of the so-called ethereal tinctures.