Much attention has been recently bestowed on the medical properties and uses of carbonic acid in its pure gaseous form. Towards the close of the last century, it was brought into notice, as an anaesthetic agent, by an experiment of Ingenhousz, who found that a finger, deprived of its cuticle, and introduced into oxygen gas. became more painful; whereas, by immersion in carbonic acid gas, the pain was relieved. Acting upon this hint, several English physicians employed it remedially, injecting it into the rectum in dysentery, and applying it to painful and ill-conditioned ulcers on the surface; and Mr. Ewart, a surgeon of Bath, obtained great benefit from it in cancer of the breast. The direct application, however, of the pure gas seems to have fallen into entire neglect; though it has ever since continued to be employed, in the form of effervescing draughts, for the relief of irritable stomach, and in that of fermenting poultices, for gangrenous ulcers. In 1834, M Mojon, of Genoa, recommended the injection of the gas into the vagina in dysmenorrhoea, and other painful affections of the uterus; and the practice seems to have been imitated by other Italian physicians. About the same time, it was employed at certain mineral springs in Germany and France, in the form of air-bath and of the air-douche, for rheumatic pains and various other affections; the gas being used as it issued from the natural fountains. But it is to Sir J. Y. Simpson, of Edinburgh, that we are mainly indebted for the revival of this remedy, and the much more extended use now made of it. Having seen a notice of its efficacy in a case of uterine disease, under the care of Dr. Rossi, of Italy, he was induced to give it a trial, and made his experience with it public, in an essay upon the subject, written, in 1856, for the New York Academy of Medicine.


When a stream of carbonic acid gas is directed upon a sensitive surface, as of the mucous membranes, or the skin denuded of the cuticle, it produces at first an irritation, variable in degree according to the sensitiveness of the surface, and sometimes very painful, especially in the conjunctiva, which, it is said, cannot support the application longer than 4 or 5 seconds. In the nasal passages it produces an effect analogous to that of ammonia, and, when the attempt is made to inhale it, either unmixed, or diluted with 50 per cent, or less of atmospheric air, it causes so much irritation in the larynx that the glottis closes spasmodically, and its entrance into the lungs is prevented. (Herpin, Ann. de Therap., 1859, p. 60.) This property of carbonic acid gas has been long known; and I once convinced myself of its reality by cautiously attempting to inhale the air over the surface of the fermenting liquid, in a large brewers' vat. It has been denied by Sir J. Y. Simpson, probably from the circumstance that, in the cases in which he applied the gas to the air-passages, it was much diluted with atmospheric air. (See Braithwaite's Retrospect, xxxviii. p. 260.) When mixed with 80or 90 per cent. of atmospheric air, it is inhaled readily, and without inconvenience. Its first irritant impression on the part to which it is applied is soon followed by a sedative effect upon the nervous tissue, by which pain, if present, is often entirely relieved. Even ordinary sensation is after a time much diminished, as shown by an experiment of Dr. T. A. Demme, of Philadelphia, who immersed his naked arm in the gas, and, after ten minutes, found the skin so much benumbed that it could be violently pinched without causing pain. {Med. and Surg. Reporter, Feb. 26, 1859, p. 380.) When inhaled, in the diluted, state, the gas is said to accelerate the circulation, though acting as a sedative to the nerves. After a short continuance of inhalation, it causes a state of somnolence and anaesthesia, which, according to Messrs. Faure and Ozanan. who experimented with it on the lower animals, may be kept up, without danger to life, for 10, 20, or even 30 minutes, so as to give ample time for the performance of any ordinary surgical operation. Though, in its concentrated state, it causes speedy suffocation by excluding air from the lungs, yet, when mixed with so large a proportion of common air as to be readily inhaled, it is said not to occasion sudden death, but to induce insensibility gradually, and without any violent symptoms (Herpin, Ann. de Therap., loc. cit.) If these results should be satisfactorily confirmed by experiment, carbonic acid gas would be a safer surgical anesthetic than chloroform.

Dr. CI. Bernard, of Paris, has observed that the injection of carbonic acid into the vagina is not unfrequently attended with constitutional effects, similar to those produced by its inhalation. The symptoms are headache, giddiness, abnormal sounds in the ear, nausea, somnolence, languor and prostration, and even involuntary discharges of urine; and he has sometimes found them so threatening as to preclude the use of the remedy. He noticed the effect as well in cases in which the surface of the vagina retained its integrity, as in those in which there was ulceration.

From a series of experiments by MM. Ch. Leconte and J. Demarquay, of Paris, on the effect of gases injected into the subcutaneous cellular or areolar tissue, or cavity of the peritoneum, it has been satisfactorily determined that carbonic acid thus injected produces no injurious effect; being absorbed in forty-five minutes; and that, consequently, no hesitation need be felt in applying it in this way, when from any cause indicated. (Arch. Gen., Oct. 1859, p. 5G8.) Now, as carbonic acid gas has proved anaesthetic under various circumstance's of application, it would probably be found so if injected into the areolar tissue. At least it might be worth the trial, in cases of obstinate local pains which have resisted other anaesthetics, or in which there may be some objection to their use. MM. Leconte and Demarquay also ascertained that this gas, brought into contact with divided tendons, facilitated their union.

Uses. The affections in which the gas has been found most useful, when topically applied, are painful stales of the uterus and vagina, with or without ulceration. Great relief is afforded in cancerous cases; and sometimes ulcers of this character, at the neck of the womb, are said to have been much benefited, and even healed under its influence. (CI. Bernard, loc. cit.) The anodyne influence of the gas is sometimes preceded by severe burning pain, which is diffused through the pelvis; and this is said occasionally to be so inconvenient as to prevent the use of the remedy. But in general the uneasiness, if produced, soon subsides, and is followed by the anesthetic effect The application may be repeated twice or three times daily; and each time may continue fifteen minutes or longer; but should always be suspended on the occurrence of constitutional symptoms.

Much relief is also asserted to have been obtained from the remedy in irritable stales of the bladder, with painful micturition. It is injected through the urethra, by means of a double catheter, by which injurious accumulation and distension of the viscus are prevented. Sometimes, as from injections into the vagina, the pain is very severe. According to Dr. Robert Johns, of Ireland, who has had considerable experience with the remedy, it should not be repeated, as a general rule, oftener than once daily, and the bladder should be well washed out with warm water before the application. (See Am. Journ. of Med. Sci., N. S., xxxvi. 561).

In the tenesmus of dysentery relief may be expected from the injection of carbonic acid gas into the bowels; and it has been already stated that this use of the remedy was made before the commencement of the present century.

The same is true of its employment in external cancer and other ill-conditioned ulcers; and Sir J. Y. Simpson recommends it in wounds and burns. It is said not only to relieve the pain of these ulcers, but to promote their cure.

In the photophobia attendant upon scrofulous disease of the conjunctiva, a stream of the gas properly diluted has been found useful; but its intensely irritating effect, when too concentrated, must be borne in mind. Good might be expected from it in that not uncommon, and very painful affection, in which exposure to light produces great suffering, from an over-sensitive state of the retina. In a case of severe earache, Dr. Demme obtained very favourable effects from the introduction of the gas into the external meatus. (Med. and Surg. Reporter, loc. cit).

Employed, in a much diluted state, by inhalation, it is said to have proved useful in chronic bronchitis, laryngitis, and pharyngitis, and in asthma and irritable cough. In this way it has been employed, to a considerable extent, by Bischoff and others in Germany; and, as asserted, without unpleasant effects. It is not, however, considered applicable to acute inflammation of the air-passages, or to phthisis. (See Am. Journ. of Med. Sci., April, 1859, p. 543.) Should the remedy be used by inhalation, its application should be watched by skilful persons, and the danger of fatal asphyxia be most carefully guarded against. The physician could not be held unaccountable, should serious consequences occur, either through his own carelessness, or the ignorance of those to whom he may entrust the use of the remedy.

Mode of Application

The most convenient method of applying the gas, is by means of a flexible caoutchouc or gutta percha tube, proceeding from a bottle in which it is generated. A Wolfe's bottle may be used having three tubulures, into one of which the exit tube is inserted, in another a safety tube with its lower end beneath the surface of liquid in the bottle, and in the third a stopper removable at pleasure. A mixture of five drachms of bicarbonate of soda and four of bisulphate of potassa, in the form of powder, is first introduced, and, when the instrument is to be used, water is poured in sufficient to cover them. Sir J. Y. Simpson uses eight drachms of crystallized bicarbonate of soda, six drachms of crystallized tartaric acid, and four or five ounces of water. When the evolution of the gas begins to slacken, it may be increased by shaking the bottle.