mentioned above, was nothing less than impure chloroform. Mr. Jacob Bell, of London, it appears, was the first to procure it in a pure state, and demonstrated anew its wonderful anæsthetic properties. As early as 1831, Dr. Gutherie, an American chemist, had shown that this substance is procured when spirit of wine is distilled with chloride of lime. But its true chemical composition, which had puzzled Professors Silliman, Liebig, and Soubeiran, was finally determined by Professor Dumas, of Paris, in 1832.

On the 8th of March, 1847, M. Flourens stated, at the Paris Academy of Sciences, that he had experimented with chloroform upon different animals, and had ascertained that it invariably produced insensibility; but he concluded that its action was too dangerous to be applied to man. However, in November of the same year, Professor Simpson, of Edinburgh, applied chloroform, for the first time, to annul the pains of labour, and it has since completely dethroned ether in surgical operations.*

Dr. Gregory, of Edinburgh, afterwards showed that the action of ether and chloroform is precisely similar to that of nitrous oxide gas. When either of the two former is inhaled in insufficient quantity, the patients are given to laughing, dancing, &c., as if they had respired a dose of "laughinggas."

It is certainly wonderful, when we reflect upon the fact, that these volatile liquids, whilst rendering us insensible to pain, cause the patient to experience pleasant sensations whilst under the knife of the surgeon. Before referring to any other means of rendering man insensible to suffering, let us take a rapid glance at the manner in which these remarkable anæsthetics act upon the system.

Under the influence of chloroform and ether, the nervous centres lose their powers in regular succession. This is not only an interesting physiological fact, but also a practical point of great importance. First, the cerebral lobes lose their influence, and consciousness disappears entirely. Next, the cerebellum loses its power of regulating locomotion. Next, the spinal cord becomes incapable of producing sensation and of originating motion; but the medulla oblongata (that portion of the spinal cord which enters the brain), which presides over respiration, still retains its functions. Next, the medulla oblongata is affected; when this occurs breathing ceases, and

* Ether has often been applied with success to subdue intoxication by wine, as we see the betel-nut employed by the Eastern princes to dispel the effects of haschish; after inhaling a little ether vapour, the intoxicated person generally recovers his senses. Ammonia acts in a similar manner.

death is near; but, even yet, the ganglionic nerves of the sympathetic system perform their functions, and the heart and intestines continue to move for a time, often with vigour.

It is thus seen that when anesthetic vapours are inhaled the different nervous centres lose their powers in the inverse order to their essentialness to life; the functions of the sympathetic nerves ceasing last of all, and the heart and womb retaining for a time, therefore, their contractile power during states of anæsthesia, so deep as not only to involve the annihilation of consciousness and sensibility, but also of respiration. In order to render a patient insensible to the most severe surgical operations, it is never necessary to proceed further than the third stage of anæsthesia; in child-birth still less is required, and the patient may be kept on the borders of consciousness, or be conscious even during the whole time.

Here, then, in a few words, is the explanation of these wonderful phenomena.

In the human body exist, as I stated before, different systems of nerves, and the art of producing anæsthesia consists in allowing one system to work as usual whilst the other systems are under the influence of sleep. The nerves of motion and of sensibility are made to sleep, whilst the nerves of organic life continue their functions. We are now enabled to appreciate these wonderful discoveries, and to admire the marvellous arrangement of the nervous system. The problem of depriving man of sensibility and motion, without impeding respiration, circulation, digestion, or, in other terms, of depriving him of his faculty of moving and of feeling pain, without depriving him of life, has been solved. During anæsthesia, then, man lives like a plant-his animal faculties are taken from him for a time.

Since the discovery of chloroform, several substances have been found to have a similar wonderful action upon the nervous system. Among them are two chemical products, called Amylen and Acetone.

Amylen, a peculiar volatile liquid, obtained from impure potato spirit, was first administered by Dr. Snow, at King's College Hospital, London, in November, 1846; and he continued to use it until July, 1857. During this period, 238 persons were operated upon during anesthesia produced by amylen, out of which number only two deaths occurred. It was afterwards used in France; but I do not know that it possesses any advantage over chloroform.

In 1859, Dr. Kidd proposed the use of Acetone (a volatile liquid, produced by distilling acetate of lime, and which has long been known to chemists) as a powerful anæsthetic. Its agreeable odour, which resembled somewhat essence of mint

or of quince, appeared to recommend it. Its anæsthetic action is less durable than that of chloroform, but, at the same time, it acts very rapidly. Its principal advantage was stated to reside in the fact that it can be mixed with water in any proportion, so that the dose can be regulated at will; it can, moreover, be employed in damp, warm sponges, and is not liable to decompose by keeping.

Of late years, cold has been applied in some cases to induce local anesthesia. Dr. John Arnold has advocated the induction of insensibility by freezing the part to be operated upon. This is based upon the fact that the nerves of sensibility cannot perform their functions below a certain temperature. Thus it is that travellers on the summits of high mountains or in the Arctic regions are apt to lose their noses, the nerves of the frost-bitten part being benumbed by the cold; gangrene sets in without the sufferer being aware of it.

Local anesthesia has also been produced by the simultaneous actions of electricity and a narcotic. Some experiments were made upon this subject by Dr. Richardson, in 1859. This method of proceeding is very simple:-Upon the part to be operated a powerful narcotic is applied, and upon the narcotic mixture is placed a flat metallic disc communicating with the · positive pole of a Bunsen's or Grove's battery; the negative pole being applied to some other portion of the patient's body, at a convenient distance from the other pole. The battery being put in action, that part of the patient's body comprised between the two poles soon becomes insensible to pain.

Dr. Richardson has also made the curious discovery that the fumes emitted by burning the common Puff-ball Fungus (Lycoperdon proteus), when inhaled, produce anesthesia in a similar manner to chloroform and ether. The fumes of this fungus have been for some time employed with advantage to stupefy bees before taking their honey; it causes no injury to these useful insects. This fact probably led Dr. Richardson to try its effects upon other animals, and, lastly, upon man; when he arrived at the conclusion that the fumes given off by the common puff-ball, when this fungus is burnt upon a hot shovel, possess anæsthetic properties in a high degree.

Carbonic acid gas has been shown quite recently, by Dr. Ozanam, of Paris, to be capable of inducing anæsthesia like chloroform, &c. Indeed, its peculiar stupefying action is frequently experienced by the French cooks, in whose kitchens wood-charcoal is used in small open grates; and by the inmates of counting-houses and warehouses, where ventilation is generally bad. The effects of this deleterious gas upon dogs is frequently shown to travellers near Naples in the grotto del Cane, a cavern where a large quantity of carbonic gas issues

from the earth, and from its weight, much greater than that of air, forms a thick stratum of suffocating gas upon the floor of the cavern. When a man enters, his head and shoulders rise above the stratum of gas, and he breathes pure air; but when a dog is introduced, his head and body plunge completely into the carbonic acid gas, and he soon falls down, suffocated. The animal is then removed by the guide, laid upon the grass outside, and, in a short time, recovers.

Dr. Ozanam has shown that this suffocation by carbonic acid, when produced properly, affects a patient like chloroform, ether, or nitrous oxide, and can be made available in surgical operations. Indeed, he considers that carbonic acid has certain advantages over chloroform, and that it is less dangerous than

the latter.

But of all the means hitherto employed to render man perfectly insensible to pain, the most curious, perhaps, is that called Hypnotism or Braidism, discovered many years ago by the late Dr. Braid, of Manchester, and practised successfully by him in England. It consists in placing some object, such as a cork or a piece of polished metal, at a short distance from the forehead of the patient, and requesting him to fix his eyes steadfastly upon it. After some time, which varies from a few minutes to half an hour or so, according to the constitution of the individual, the patient's eyes seem riveted upon the object in question, and for some moments he remains thus, without once closing them; they then suddenly close, and the patient falls into what is termed the hypnotic state, a kind of somnambulism similar to mesmerism. Consciousness has disappeared, and complete insensibility to pain has ensued.

Braid's discovery seems to have been abandoned for some time past by the medical world, but was occasionally put in practice by lecturers on the so-called "electro-biology," &c. Lately, however, it has been taken up again in Paris, by M. Paul Broca, surgeon to one of the hospitals of that city; and Dr. Braid just lived long enough to hear of his method of producing anesthesia meeting with singular success in the hands of M. Broca. One of the first results obtained by the latter was made known a year or so ago at the Académie de Médecine. It was the case of a woman who had repeatedly refused to be operated upon for a large tumour. At length, M. Broca induced anæsthesia by causing the patient to fix her eyes upon a metallic disc which he held above her forehead. In about a quarter of an hour, a state of complete insensibility supervened, and the operation was performed. On returning to her senses, the poor woman would not believe that the operation had indeed taken place whilst she was under the influence of sleep.

or of quince, appeared to recommend it. Its anæsthetic action is less durable than that of chloroform, but, at the same time, it acts very rapidly. Its principal advantage was stated to reside in the fact that it can be mixed with water in any proportion, so that the dose can be regulated at will; it can, moreover, be employed in damp, warm sponges, and is not liable to decompose by keeping.

Of late years, cold has been applied in some cases to induce local anesthesia. Dr. John Arnold has advocated the induction of insensibility by freezing the part to be operated upon. This is based upon the fact that the nerves of sensibility cannot perform their functions below a certain temperature. Thus it is that travellers on the summits of high mountains or in the Arctic regions are apt to lose their noses, the nerves of the frost-bitten part being benumbed by the cold; gangrene sets in without the sufferer being aware of it.

Local anesthesia has also been produced by the simultaneous actions of electricity and a narcotic. Some experiments were made upon this subject by Dr. Richardson, in 1859. This method of proceeding is very simple :-Upon the part to be operated a powerful narcotic is applied, and upon the narcotic mixture is placed a flat metallic disc communicating with the· positive pole of a Bunsen's or Grove's battery; the negative pole being applied to some other portion of the patient's body, at a convenient distance from the other pole. The battery being put in action, that part of the patient's body comprised between the two poles soon becomes insensible to pain.

Dr. Richardson has also made the curious discovery that the fumes emitted by burning the common Puff-ball Fungus (Lycoperdon proteus), when inhaled, produce anesthesia in a similar manner to chloroform and ether. The fumes of this fungus have been for some time employed with advantage to stupefy bees before taking their honey; it causes no injury to these useful insects. This fact probably led Dr. Richardson to try its effects upon other animals, and, lastly, upon man; when he arrived at the conclusion that the fumes given off by the common puff-ball, when this fungus is burnt upon a hot shovel, possess anæsthetic properties in a high degree.

Carbonic acid gas has been shown quite recently, by Dr. Ozanam, of Paris, to be capable of inducing anæsthesia like chloroform, &c. Indeed, its peculiar stupefying action is frequently experienced by the French cooks, in whose kitchens wood-charcoal is used in small open grates; and by the inmates of counting-houses and warehouses, where ventilation is generally bad. The effects of this deleterious gas upon dogs is frequently shown to travellers near Naples in the grotto del Cane, a cavern where a large quantity of carbonic gas issues