The rapidity with which the patients came under the anesthetic influence of hydrobromic ether. Ten cases in one minute and a half, twenty in two minutes, ten in two minutes and a half, forty in three minutes, ten in four minutes, ten in five minutes. How long did it take to recover consciousness from the effects of the hydrobromic ether? In fifty cases from two minutes to two minutes and a half; in thirty cases, three minutes; and in twenty cases, four and a half to five minutes. Struggling, coughing, or gagging, which occurs so frequently during etherization, was very rare under the anesthetic influence of hydrobromic ether. This form of anaesthetic is not apt to produce headache.

Hydrobromic Ether as an Anesthetic in Labor.-In some instances, in labor, both ether and chlorform will produce, in certain females, so much relaxation of the sphincters, that if there is the slightest tendency to hemorrhage, it will be very much increased. To test the influence of hydrobromic ether, I administered it February 24, 1880, to Mrs. R. T. P., aged 30, a lady with a narrow pelvic outlet, and very rigid os uteri, who had been in labor with her fourth child for nine hours, having made but little progress. The hydrobromic ether was used in tablespoonful quantities, when the pains were most intense and distressing, and gave as prompt relief as ether, and yet it did not interfere in the least with the expulsive efforts. Her pulse was only increased six beats; no apparent disturbance of her respiration, only a feeling of fulness in the chest. The baby, a female, was born, full of life and vigor, and cried lustily. There was a slight laceration of the perineum, as the occiput was pressed strongly upon the tissues. The patient had not a bad symptom from the use of this form of anaesthetic, and there was no sickness of the stomach. The whole quantity employed was five tablespoonfuls. There was no hemorrhage, and the placenta was expelled with but slight traction. This is the first time that I am aware of this agent having been employed for this purpose. In a second case I employed this anaesthetic with a like good result; and it has been employed by others.

Method of Using it.-The hydrobromic ether is best given in a folded, starched napkin, so as to cover the face, and inside that a soft pocket handkerchief, or second napkin. Twice I have found that, unless the first drachm was crowded upon the patient, it is apt not to act promptly. This has been the cause of failure in two or three instances, in the hands of able surgeons.

I have met with one or two specimens of hydrobromic ether which, on standing, would become brown, from free bromine; some of the specimens also had a most disagreeable odor of bromoform, and others of free phosphorus. Another specimen was mixed with ordinary ether, and would explode and burn. One of the greatest advances in its use by the profession was the obtaining of a formula free from the explosive article, phosphorus, and furnished at a moderate cost; the full formula will be found in my work. This process of De Vrij, by decomposing potassii bromidum with sulphuric acid, which process was modified by Dr. Greene, has since been changed, so as to obtain a larger quantity, by Dr. L. Wolff, who recommends the use of a larger quantity of sulphuric acid and water, with ferri bromidum, on account of its cheapness, and its distillation at a lower temperature (about 200° F.), and throwing away the very first and latter part of the product.

In April, 1880, there was published' a valuable article on bromide of ethyl, or hydrobromic ether; its physiological action. The author in his experiments agrees with those made by Nunnelly, Rabuteau, and myself, both on animals and man, and his conclusions are, we consider, those that would naturally flow from his experiments. I will, therefore, give his experiments, with the feeling that they will be of interest in this connection. "The period in which anesthesia was produced, according to Dr. Turnbull, varied from thirty seconds to four minutes, the average time being two minutes. The quantity required for an anæsthetic effect was from a drachm to half an ounce. In some cases it produced vomiting, excitement, and prostration, but neither syncope nor asphyxia was seen to take place. In dogs, rabbits, and frogs, it had a rapid action.2

The fact that bromide of ethyl is an anesthetic less dangerous, and at the same time quicker, than chloroform and ether, makes it a drug of vast importance both to the profession and their patients. On this account, I have thought it worth my time to make a more critical analysis of its action upon the nervous, cardiac, and respiratory apparatuses. My experiments

1 Bromide of Ethyl: its Physiological Action. By Isaac Ott, A.M., M.D., late Lecturer on Experimental Physiology, University of Pennsylvania. Reprint 16 pp., from Detroit Lancet. Geo. S. Davis, publisher.

2 Philadelphia Medical Times, Jan. 1880.

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were performed upon the lower animals, frogs and rabbits. To irritate, I employed a Dubois induction apparatus, run by a small carbon-zinc cell. The electrodes were those of Ludwig.

MOTOR NERVES.

To study the action on motor nerves, frogs were selected, and, after apparent death, the sciatic nerve was bared, and its irritability tested by the faradic current. The weakest current that would cause a muscular contraction was taken as a test.

EXPERIMENT I. (frog).—Was ethylized till completely relaxed, apparently dead; the sciatic was bared, and its irritability tested by the faradic current; the foot began to twitch with the secondary coil, at 265 millimetres. This experiment demonstrated that the paralysis did not ensue from a loss of power in the motor nerves. After the apparent death of the frogs, they finally recovered all their functions.

MUSCLE.

To

Upon striated muscle, bromide of ethyl has the power to lower the irritability. Thus, when curves are taken of a muscle, the height of the curve seldom reaches that of a normal curve. take the curves, I employed a myograph of Marcy, the muscles being loaded with a weight of ten grammes. This instrument inscribed its tracings upon the cylinder of a Marcy-Secretans apparatus. The time was registered by a tuning-fork, registering 120 double vibrations, being run by a large Daniell cell. Aş is seen in Fig. 2, the ascent of the curve is normal, the summit slightly larger, and the descent considerably prolonged. Direct irritation was employed. Figs. 2 and 3 represent the effect of ethyl, Fig. 1 the normal muscle curve.

SENSORY NERVES.

To test the action of the sensory nerves, I employed the following method:

EXPERIMENT II. (frog).-Had his right thigh ligatured, excepting the sciatic, then his nose was plunged into the vapor of bromide of ethyl. In a few minutes he was completely relaxed. Upon pinching the right foot, no movement ensued; the same result ensued with the other feet. The lymph hearts continued beating during the anesthesia.

EXPERIMENT III. (frog).-His abdominal aorta was ligated, and his nose plunged into the vapor of ethyl for a few minutes, when he was completely anæsthetized. Upon pinching his feet, or irritating them electrically, no movement followed in any ex

tremity, although each extremity was irritated. As already demonstrated, the motor nerves remained irritable, whilst the muscles were somewhat affected, yet not so much that they would not contract upon an impulse being communicated to them through the motor nerves. The experiments above demonstrate that the sensory nerves are not affected. They convey impressions to the spinal cord, but this organ takes no cognizance of them, or, if it does, we are unable to evolve any proof of this cognizance. This brings us to the consideration of the spinal cord itself.

EXPERIMENT IV. (frog). His spinal arteries coming from the abdominal aorta were severed, and his nose was plunged into the vapor of bromide of ethyl. The reflex movements of the posterior extremities continued a considerable time after they vanished in the anterior ones.

As already stated, the seat of the paralysis is neither in the motor nerves, muscles, nor sensory nerves, but in the spinal cord. Experiment IV. also confirms this view, for here the ethyl only reached the upper segment of the spinal cord at first, but, by its volatility it was diffused finally through the whole cord.

REFLEX ACTION.

In the study of reflex action I employed Türck's method. The frog was suspended by a wire holder, and its foot immersed in a solution slightly acidulated by sulphuric acid, and then the acid was immediately washed off. The time was noted by a metronome, beating ninety times per minute. The cerebrum was always ablated, and the animal permitted to recover.

EXPERIMENT V. (frog).—Medulla separated from the cord.