For many hours after the immediate effects of the inhalation of ether are over, there is an escape of its vapour from the lungs, and possibly from other emunctories, which is obvious to the senses of an observer, and which sometimes continues, according to my own observation, for one or two days or more. So striking is this effect, that a patient who has inhaled ether at bedtime, will often scent a large apartment next day with its odour. There is also sometimes a sensation of heat in the chest, attendant on the exhalation of the vapour, indicating that it is escaping by the lungs.

* But very few cases of death, under the influence of ether used as an anaesthetic agent, are on record. I have seen a detailed notice of but one case. It was that of a woman in New York, for whom the inhalation of ether was used to relieve violent pain in the head. A large tumour was found in the cerebellum, which was probably the real cause of death, perhaps aided by the additional stimulus of the ether, which had been given three times previously without unpleasant effects. (See Boat. Med. and Surg. Journ., lxi. p. 245.) In the same journal (liii. 231), a case of hemiplegia is recorded following the use of ether, given in anticipation of a surgical operation. When it is considered how extensively ethereal inhalation is used in this country, both by surgeons and dentists, it is remarkable that accidents have not been more frequent. At a meeting of the Imperial Society of Medicine, of Lyons, Dr. Barrier stated that, to his knowledge, there were only three well authenticated cases in which ether had caused death, and that in these there were extenuating circumstances. (Pharm. Journ. and Trans., July, 1859, p. 41.) - Note to the second edition.

Since the publication of the last edition of this Treatise, though a very few cases of death following the use of ether have been recorded, I have seen none, in which the details were given, which could be ascribed to the direct and unmixed influence of the ether, or which ought to deter from the use of this anaesthetic in cases not obviously unsuited to it, as in those with existing disease of the brain, or with a strong predisposition to it. See on this subject a paper by Dr. F. D. Lente, in the Am. Journ. of Med. Sri. (April, 1861, p. 360). - Note to the third edition.

There are two points, in connection with the influence of ethereal inhalation, which, though strictly pathological, and, therefore, not belonging exactly to the physiological effects of ether, may be most conveniently considered in this place, in order that the whole series of facts in relation to the influence of the process may be presented in one view. I allude to the anaesthetic influence of etherization by the lungs, and that which it exercises in relaxing spasm.

That ether is capable, when inhaled, of abolishing sensibility, is an obvious corollary to its stupefying power. The sense of touch, as well as every other special sense, is, in the very nature of the case, suspended in coma. This, then, is no new discovery. But it was not so obvious that the general sensibility might be diminished and even quite suspended, while consciousness, and, to a considerable degree, the special senses, remain unaffected. This, however, is a most important fact in relation to etherization. Under the influence of this agent, pain is often abolished if existing, and averted when it would otherwise have been produced, before the occurrence of any degree of stupor, or of any considerable anaesthesia of hearing, sight, etc. The woman in childbed ceases to suffer from her labour-pains, though still conscious; the patient under the knife of the surgeon sometimes scarcely suffers, though he may follow every step of the operation; and the pain of violent spasm is subdued as by a charm, without the least degree of apparent stupefaction. An eminent medical gentleman once assured me that, while labouring under the most exquisite pain from spasm of the bladder, he had inhaled ether, with the effect of completely relieving the pain, though he retained his consciousness unimpaired, and even took pleasure in noting the return of each contraction of the bladder, of which he was distinctly sensible, though it was quite painless.

The other point referred to was the efficacy of ether when inhaled in relaxing spasm. That it should have this power, in reference to the voluntary muscles, so far as the cerebral centres are concerned, was almost inferrible from the property it evinces in health of relaxing these muscles, when the system is brought completely under its influence. But the muscles of organic life usually remain unaffected, at least not materially affected, in the stupefaction, unless carried to the last degree short of absolute death. Respiration goes on; the peristaltic movements, so far as is known, are not impaired; the sphincters generally act as in health; and the uterine contractions during labour are undiminished in force, though no longer painful. But over the morbid contractions of these muscles, over their spasmodic conditions, for example, etherization has great control. It is capable not only of relieving the pain of these spasms, but, in a somewhat higher degree of its action, of relaxing the spasms themselves. Though, as before stated, the spasm will sometimes continue after the pain has ceased, yet the two often cease together, and, when this is not the case, the muscular relaxation generally soon follows the anaesthetic effect. This only proves that the nervous centres of pain, and those of the involuntary movements, are not the same, and that the former usually come under the influence of the anodyne before the latter. The pains of tetanus, for instance, cease before the muscular spasms, but these also will often yield, temporarily at least, to ether. In their tetanic movements, the muscles cease to be voluntary muscles; and are under the control of the spinal centres. From all this, it may be physiologically deduced that, in etherization, the nervous centres of organic life, those, namely, of the spinal marrow, and the sympathetic ganglia, either come last under the power of the stupefying agent, or, to speak more precisely, are the least susceptible to its action.

Another valuable therapeutic agency of ether by inhalation is the relaxation it often produces in the mucous tissues, with an increase of the mucous discharge. This has been noticed in the mucous membrane of the generative organs of women in childbed, and in the bronchial tubes, and may possibly extend to the others; as it is probably rather through the organic nervous centres that it acts, than directly on the tissue affected.

Judging from the effects above detailed, we may pretty certainly conclude that the cerebral centres of general sensation, and those of thought and emotion, are most susceptible to the influence of ethereal inhalation, that next in order are those of special sensation and the will, and that lower still in the scale of susceptibility are the centres of organic force, of which the respiratory centre in the medulla oblongata is the lowest.

Perhaps there is no powerful remedy to which the system becomes more speedily accustomed than this; so that, to sustain a given effect for a long time, it must be administered on successive occasions, in rapidly increasing quantities; and the amounts which have been given, in some cases, without material injury, are almost astounding, considering the powerful effect produced at first by a small quantity, and the rapidity with which the larger amount has been reached. Even while the ether, which may have caused all the characteristic phenomena, still remains in great measure in the system, it has quite lost its effects on the cerebral centres; for the breath continues to smell of it long after all the phenomena of its action have disappeared. The previous habit of using alcohol or opium also greatly lessens the susceptibility to the impression of ether, showing a close resemblance between these three cerebral stimulants in their mode of action.

The only morbid appearances noticed after death from ether are those incident to asphyxia; namely, darkness of the blood, fulness of the right cavities of the heart, and congestion of the brain, lungs, etc.

In poisoning from ethereal inhalation, the shock of cold water upon the face, head, or shoulders, and the introduction of pure air into the lungs by artificial respiration, are probably the most efficient measures. When the prostration is great, the ammoniacal stimulants may be resorted to by the mouth or rectum, and external stimulation by rubefacients should not be neglected.