On chloroform and other anæsthetics: their action and administration

This substance was discovered and described in 1844 by M. Balard, Professor of Chemistry to the Faculty of Sciences of Paris.^[172] M. Auguste Cahours had given this name five years previously to a product which is isomeric with amylene, and is produced at the same time, but is now termed paramylene.

Amylene is made by distilling amylic alcohol with chloride of zinc. The amylic alcohol is obtained from crude fusel oil, otherwise called oil of grain, or oil of potatoe spirit. The fusel oil must be submitted to a careful distillation, with a thermometer in the retort. It begins to boil at a comparatively low temperature, but that portion only is to be retained which comes over from 266° to 284° Fah. Caustic potash is added, to decompose the œnanthic ether which the distilled liquid contains, and it is then redistilled, and that portion which boils steadily at 270° Fah. is collected as pure amylic alcohol. Amylene can be obtained from amylic alcohol in the same manner that olefiant gas, or ethylene, can be made from common alcohol, namely, by heating it with dishydrating agents, as sulphuric, phosphoric, fluoboric and fluosilic acids, and chloride of zinc; but most conveniently with the last substance, which is the one that M. Balard employed. The product which is obtained when amylic alcohol and chloride of zinc are distilled together, contains at least three distinct hydrocarbons, amylene, paramylene, and metamylene; and the amylene which is the most volatile is separated from the others by successive distillations.

Amylene is a colourless and very mobile liquid, of extremely low specific gravity; being one of the lightest liquids known. The amylene made for me by Mr. Bullock^[173] had a specific gravity of 0·659 at 56°. It is very volatile, boiling at 102° Fah. according to M. Balard, and at 95° according to Frankland, and the specific gravity of its vapour is 2·45. It is composed of ten atoms carbon and ten atoms hydrogen, and bears the same relation to amylic alcohol that olefiant gas, or ethylene, bears to common alcohol.

It is inflammable, burning with a brilliant white flame; and in pouring it out by candle light, the same care is required as in dealing with sulphuric ether. A slight explosion may be obtained by applying a light to a mixture of a small amount of its vapour with a large quantity of air.

It is soluble in alcohol and ether in all proportions, but is very sparingly soluble in water, being in fact a hundred times less soluble than many substances which are ordinarily spoken of as insoluble. From a number of careful experiments which I made, I found that water dissolves 2·35 per cent. of its volume of the vapour of amylene. It follows therefore, from the specific gravity of amylene and of its vapour stated above, that amylene requires 9319 parts of water for its solution. The water which has dissolved this small quantity of amylene tastes as distinctly of it as amylene itself.

Amylene has more odour than chloroform, but much less than sulphuric ether, and the odour does not remain long in the patient’s breath. The smell of amylene somewhat resembles that of wood spirit. The first specimens which Mr. Bullock made were slightly offensive, but the odour improved and diminished in strength, as he obtained the substance in a state more nearly approaching to purity. Many persons, who thought the odour disagreeable at first, began to like it after they had been exposed to it three or four times. It is almost without taste, and it produces no irritation, or effect of any kind on the sound skin, even when confined, and prevented from evaporating. The vapour is almost entirely without pungency, furnishing in this respect a remarkable contrast to both ether and chloroform. Its presence can be perceived on first beginning to inhale it, but after two or three inspirations, one cannot tell whether the air one is breathing contains any of the vapour or not. It does not cause any cough unless there is great irritability of the air-passages, or the vapour is breathed of great strength in the very first inspirations.

Amylene produces about as much cold during its evaporation as sulphuric ether does. If a sponge or piece of blotting paper wetted with amylene is exposed to the air, a portion of the moisture of the air becomes condensed on its surface, by the cold caused during the evaporation of the amylene; and by the further effect of the cold the condensed moisture is frozen, and the sponge or paper is covered with hoar frost.

The boiling point of pure amylene would probably be that which I have quoted above from Frankland, viz., 35° cent. or 95° Fah.; but the amylene which has been obtained for inhalation contains other hydrocarbons of an analogous composition, and its boiling point is not steady: 95° Fah. was indeed about the average boiling point of the greater part of the amylene furnished to me by Mr. Bullock, for it usually commenced to boil at 86°, and as it evaporated, the boiling point gradually rose to 109°, or higher.

No method is at present known of separating amylene from the products which come over with it, except a number of distillations; and although these may be carried so far as to obtain a small quantity almost pure, the price of it would be too great to admit of its employment for inhalation. For this purpose, one must be content with a product approaching to purity. Dr. Debout, in an article on amylene,^[174] says that the boiling point commences at 28° (82° Fah.), and rises gradually to 40° or 45° (104° or 113°) in the best products which have been obtained by Mr. Bullock of London, M. Hepp of Strasbourg, and the house of Ménier at Paris.

M. Duroy published an elaborate paper on amylene, on April 9th, 1857.^[175] In this paper, he gives the result of an examination of four specimens of amylene: the first, which he calls A, was amylene made by Mr. Bullock; the second (B) was the amylene of M. Ménier; the third (C) was some that he had prepared according to the process of M. Hepp; the fourth (D) was amylene which he had obtained by a process which he described. In this process, he employed dry chloride of zinc and amylic alcohol. M. Balard recommended a solution of chloride of zinc of a certain strength to be used. I may state, however, that Mr. Bullock had from the first used dry chloride of zinc.

The following table shows the temperature at which the different specimens began to boil, and the temperature to which they rose before being boiled entirely away.

Mr. Bullock’s amylene went through the smallest range of temperature whilst boiling away.

M. Duroy found that potassium was oxidized to a certain extent in all these specimens of amylene, and a small quantity of hydrogen gas was produced, showing that they did not consist entirely of hydrocarbons, but that there distilled over with them a small quantity, either of amylic alcohol, or amylic ether.

The following table shows the cubic centimetres of hydrogen gas which were disengaged from three grammes of each of the different kinds of amylene.

Examined in this way, Mr. Bullock’s amylene showed the smallest quantity of impurity; and, next to that, the amylene made by M. Duroy.

M. Duroy found that amylene can be purified from the substances containing oxygen by distilling it again with dry chloride of zinc. He was able to obtain pure amylene, boiling steadily at 35° cent., but to get at this result he made so many distillations that he had only forty grammes of amylene from five litres of amylic alcohol.

He states that the following are the characters of absolute amylene.

To boil steadily at 35° cent.

To be without action on potassium, and to preserve that metal like naphtha.

Not to be coloured, even by prolonged contact with caustic potassa.

Not to give rise to valerianic acid under the action of hydrated potassa.

The following table shows the amount of vapour of amylene in air which is saturated with it at various temperatures. The specimen of amylene with which I made the experiments began to boil at 95° Fah.

I was not aware of the existence of amylene till 1856, or I should have tried it sooner; for I made inquiry in 1848 for a substance named eupion by Reichenbach, its discoverer, but was unable to obtain it. Eupion is a carbo-hydrogen, described as having all the physical characters which belong to amylene, though obtained in a different way; and I believe it is the same substance, or the hydride of amyle. Reichenbach obtained it from coal tar, but other chemists have not been able to make it.

Judging from experiments which I had made on analogous substances, there could be no doubt of amylene causing insensibility when inhaled; but I could not tell, without actual trial, whether it might not be unpleasant in its action.

I believe that amylene had but rarely been made, and only in very small quantity, until I requested Mr. Bullock to make it for me. For some time afterwards, soon after my first paper had appeared on the subject, M. Berthé, of Paris, made some amylene and submitted it to M. Balard, its discoverer, who acknowledged its purity, and was astonished at the great quantity M. Berthé had obtained. This quantity, however, appears to have only been forty grammes, or about ten fluid drachms.

As soon as Mr. Bullock succeeded in making some amylene for me, I proceeded to perform some experiments with it on small animals. I found that it was necessary that an animal should breathe air containing about 10 per cent. of the vapour in order to lose its consciousness, and that 20 per cent. caused a deep state of insensibility, whilst 25 per cent. could be breathed with perfect safety.

The following are a few of the experiments.

Experiment 43. A guinea pig was placed in a glass jar holding four hundred and twenty-eight cubic inches. Fifteen grains of amylene were dropped through a small tube in the air-tight cover of the jar, fell upon blotting paper suspended within, and quickly evaporated and became mixed with the air. In three or four minutes the guinea pig staggered and became altered in its manner. It did not become further affected, although it was allowed to remain for ten minutes. When taken out its sensibility did not seem impaired. Each grain of amylene produces 1·315 cubic inch of vapour, and consequently the air in this experiment contained 4·6 per cent. of vapour.

Experiment 44. The same guinea pig was placed in the same jar three days afterwards, and twenty-five grains of amylene were introduced in the same manner. At the end of two or three minutes the guinea pig seemed estranged in its manner, and turned its head from side to side. In a little time it seemed getting drowsy, but at the end of twelve minutes it was still on its legs and moving voluntarily. Eleven grains more of amylene were now introduced. In a little time it sank down unable to stand, and on being turned over by inclining the jar it made efforts to right itself, which became more and more feeble. It was taken out at the end of fifteen minutes, i. e., three minutes after the introduction of the additional amylene. It gave a slight squeak, and moved its feet and eyelids on being lifted. On being pricked it gave decided evidence of sensation. It recovered in a few minutes. There were 7·7 cubic inches of vapour in each one hundred cubic inches of air in the first part of the experiment, and eleven cubic inches in the latter part.

Experiment 45. Six fluid drachms of amylene in a little bottle were put into a glass jar of the capacity of one thousand six hundred cubic inches, and the mouth of the jar was tied over with a large piece of oiled silk. The bottle was emptied by inclining the jar, and the amylene was made to run about the sides of the jar till it had all evaporated. A guinea pig was then folded in the superabundant oiled silk beyond the string which tied it, the string was then opened, and the animal introduced into the jar without allowing any communication with the external air. The guinea pig began to be affected within half a minute, and in a minute it was lying insensible, but moved its limbs when it was rolled about in the jar. In two minutes it was flaccid, and could be rolled about without causing any resistance or muscular action. It lay relaxed and motionless till taken out at the end of four minutes, although by an occasional motion of the eyelids it seemed not altogether insensible. It was quickly taken out, but the moment it was removed it began to kick, and being pricked it flinched. It was not able to stand for two minutes, but after this it quickly recovered. Six fluid drachms of amylene weigh 240 grains, and produce 315 cubic inches of vapour; consequently there was nearly 20 per cent. of vapour in the air in this experiment.

Experiment 46. A guinea pig, a fortnight old, was placed in the jar holding 428 cubic inches, and eighty-two grains of amylene were introduced on blotting paper. It was six minutes in evaporating. The guinea pig became gradually affected, and, a minute or two before the amylene had all evaporated, it was lying unable to walk. It was allowed to remain till ten minutes had elapsed, that is, four minutes after the amylene was all converted into vapour; but it did not, apparently, become quite insensible. The limbs were never quite relaxed, and when turned over in the jar there was a little motion of the limbs and head. There was also a little quivering motion of the limbs occasionally when not disturbed, and at one time it opened and shut its mouth. On its removal, pricking the soft parts of its toes caused sometimes a slight groan. It recovered slowly and gradually. In ten minutes it was quite conscious, but not as brisk as before the experiment. There was 25 per cent. of vapour in the air the guinea pig breathed in this experiment.

Guinea pigs have a great tendency to flinch when pricked whilst they are under the influence of amylene. I did not find this to be the case with other animals.

Experiment 47. A lean, starved cat was placed in a glass jar holding 1,600 cubic inches, and 120 grains of amylene were introduced upon blotting paper. The cat became inebriated whilst the amylene was evaporating; and by the time it had all evaporated—which was four and a half minutes—the cat had sunk down in a state of insensibility. The eyes were turned downwards, so as to expose the white; but its limbs were not relaxed. In a minute or two afterwards it made no effort when rolled about in the jar. It was taken out at the end of nine minutes from the commencement of introducing the amylene. It was breathing noisily; its limbs were not relaxed; it was totally insensible to pricking of the ears and paws. It began to recover in about a minute: in two or three minutes it flinched on being pricked; it staggered for two or three minutes longer, and in ten minutes it was pretty well recovered. The amylene would produce 158 cubic inches of vapour, or very nearly ten per cent. in this experiment.

Experiment 48. A linnet was placed in a jar holding 428 cubic inches, and forty grains of amylene were introduced on blotting paper. In two minutes it had evaporated. Until it had nearly evaporated, the bird was hardly affected, only evincing a desire to escape. As soon as the amylene had evaporated, the linnet lay unable to move, but evincing consciousness and sensibility by the motion of its eyelids and eyes, and by moving its legs when it was turned over by inclining the jar. It remained in this state for three minutes, when eight grains more of amylene were introduced into the jar. The bird almost immediately closed its eyes; and it opened its bill a little, from which a little liquid flowed. The motion of its legs also ceased, and its breathing was slower. It was taken out half a minute after the last portion of amylene was introduced. It seemed quite insensible when removed, but began to recover in a few seconds. When its foot was pricked, twenty or thirty seconds after its removal, it flinched. In two or three minutes it was quite recovered. There were 12·3 per cent. of vapour in the air in the first part of this experiment; and 14·7 per cent. in the latter part.

Experiment 49. Another linnet was placed in the same jar, and forty-eight grains of amylene were introduced in the same manner. It took nearly three minutes to evaporate, hoar frost being produced on the blotting paper. The bird began to stagger when the amylene was about half evaporated; and by the time it was all evaporated, the bird was lying apparently insensible, with its eyes closed, and breathing quickly. It was allowed to remain two and a half minutes, during which it did not alter. It was often rolled about by moving the jar; and during the last minute and a half it made no effort, except once or twice a slight motion of the wings. It was taken out two and a half minutes after the amylene had all evaporated. It was quite passive, and insensible to pricking of the toes, for half a minute or so after its removal, when it began to recover, went through a stage of staggering, and was well in three or four minutes. The amount of vapour in the air, in this experiment, amounted to 14·7 per cent.

Experiment 50. Fifty grains of amylene were diffused in a glass jar holding 330 cubic inches, and a linnet was introduced by momentarily moving the lid a little to one side. It was quickly affected, and in about a quarter of a minute was lying quite insensible. It remained so, breathing quickly and naturally, and made no effort whatever when rolled about in the jar. It was allowed to remain three minutes, and there was a slight fluttering motion of the wings just before its removal. It was quite passive when removed, and insensible to pricking of the soft part of the foot. It began to recover its sensibility in three-quarters of a minute. In two minutes it was able to stand, and in six minutes it got on the perch. There was twenty per cent. of vapour in the air in this experiment.

As amylene boils nearly at the temperature of the blood, that fluid would be able to absorb about one-fifth as much as it would be able to dissolve, when an atmosphere is breathed containing twenty per cent. of the vapour, which produces a complete state of insensibility, or the fourth degree of narcotism. When ten per cent. is breathed, which has been shown to cause the second degree of narcotism, about one-tenth as much vapour as the blood would dissolve must be absorbed. In treating of chloroform and ether, it was previously shewn that the fourth degree of narcotism was caused by one twenty-eighth part as much of these agents as the blood would absorb; and the second degree by one fifty-sixth part. And these were the proportions absorbed of several other agents which are made from ordinary alcohol, and will afterwards be mentioned.

Although the proportion of amylene absorbed is large in relation to the whole quantity which the blood would dissolve, it is a very small amount on account of the extremely slight solubility of the agent. If we estimate the average amount of serum of the blood in the human adult at 410 fluid ounces, as before, then, as amylene requires 9,319 parts of watery fluids for its solution (as nearly as I could ascertain), the quantity of this agent in the system must be rather less than three grains in the fourth degree of narcotism; rather less than a grain and a half in the second degree; and a very little over two grains in the third degree of narcotism, the condition in which surgical operations are usually performed. Amylene is therefore, when absorbed, about as powerful in its medicinal properties as the alkaloids.

The following fact also proves that but a very small quantity of amylene is absorbed. In breathing this agent backwards and forwards from a small bladder containing 200 cubic inches of air, fourteen minims was the largest quantity I could put into the bladder without being rendered unconscious; but in employing a large bladder holding 670 cubic inches, I could put in forty-five minims, and breathe it backwards and forwards for some time without being rendered unconscious. With fifty minims of amylene I immediately forgot where I was; but awoke in a minute or two, seated in the same position, and with the bladder in my hand. Fifty minims of amylene would produce between six and seven per cent. of vapour in the bladder; and after the air in the lungs became mixed with that in the bladder, there would be rather more than five per cent. of vapour in it.

Viewed in the light of the small quantity which requires to be absorbed into the system to cause insensibility, amylene is a very powerful agent; but when considered in relation to the quantity which is consumed during inhalation in the ordinary way, it is very far from being powerful. This arises from the great tension and the small solubility of the vapour, in consequence of which it is, with the exception of a small fraction, expelled from the lungs again without being absorbed. In this respect it resembles, to a great extent, the nitrogen gas of the atmosphere, with which the lungs are always four-fifths filled, while the blood contains but a few cubic inches. It takes from three to four fluid drachms of amylene to cause insensibility in the adult.

I found, by my experiments on animals, that amylene is, like chloroform and some other agents, capable of causing sudden death by over-narcotism of the heart, and paralysis of that organ; but that it is more difficult to cause this kind of sudden death with amylene than with chloroform.

Experiment 51. One hundred and twenty grains of amylene were made to evaporate in a jar holding 330 cubic inches, and a full grown guinea pig was suddenly introduced, the cover being partly removed for a moment. It was allowed to remain for about a minute, when the breathing became of a gasping character. Being taken out, and the stethoscope applied immediately to the chest, the heart could not be heard to beat; and its action did not return, although the gasping continued for about a minute. There was nearly 48 per cent. of vapour in the air in this experiment, except that a small quantity might escape as the guinea pig was introduced. I had tried guinea pigs with smaller proportions of vapour in the air, but had not succeeded in arresting the action of the heart.

The lungs were rather congested, and the right cavities of the heart were filled, and somewhat distended with coagulated blood.

Experiment 52. A kitten, six weeks old, was placed in a jar holding 330 cubic inches, after ninety-five grains of amylene had been made to evaporate and diffuse itself. The kitten remained three-quarters of a minute in the jar, and was suddenly taken out. It was scarcely insensible on its removal, but soon became so. The stethoscope was applied, and the heart was found to be beating rapidly. The kitten quickly recovered.

One hundred and six grains of amylene were made to evaporate in the same jar, and the kitten was quickly introduced, as before, by moving the cover for a moment. It was allowed to remain for half a minute, and removed with the same symptoms and result as before.

The same quantity of amylene was employed, and the kitten was introduced again, and allowed to remain for fifty seconds. On its first removal the heart was not beating, but the kitten was gasping; and just afterwards the heart was heard to be beating rapidly. The kitten quickly recovered.

One hundred and twenty grains of amylene were allowed to evaporate in the jar, and the kitten was introduced again. It was allowed to remain a minute, and was taken out as the breathing appeared to be on the point of ceasing. The heart was beating when the stethoscope was employed, and the kitten quickly recovered. It seemed impossible to kill it with amylene, except by allowing it to remain and inhale the vapour, by those gasping inspirations which took place when the action of the heart was arrested, and which restored the action of this organ, when the kitten was withdrawn from the vapour. In the different parts of this experiment there were 37, 42, and 47 per cent. of amylene in the air.

When mice are placed in air containing 30 per cent. and upwards of vapour of amylene, they usually recover, as in the following experiment, if the breathing has not entirely ceased on their removal; whilst if they are placed for a quarter of a minute in air containing 8 or 10 per cent. of vapour of chloroform, they generally die, although they may be breathing well, and hardly insensible, when they are removed.

Experiment 53. Eighty grains of amylene were introduced into a jar holding 330 cubic inches, and when it had evaporated, a white mouse was introduced. In about five seconds it was quite insensible, and in about a quarter of a minute the breathing appeared to have ceased. The mouse was quickly withdrawn, and immediately began to gasp. After a few gasps the quick breathing returned. In half a minute after its removal the mouse was recovering, and it was soon quite well. There was 32 per cent. of vapour of amylene in the air in this experiment.

I administered amylene with the inhaler which I had used for several years in exhibiting chloroform, and which I have described in treating of that agent. In administering chloroform it is desirable that the patient should breathe 4 or 5 per cent. of the vapour in the air he inspires; and the air, when saturated with vapour of chloroform at 60°, contains 12 per cent., or nearly three times as much as the patient ever requires. In administering amylene for surgical operations, it is desirable that the patient should take in 15 per cent. of the vapour with the air he breathes; and air, when saturated with this vapour at 60°, contains 465. per cent., or fully three times as much as the patient ever requires. It therefore seemed reasonable that the inhaler which had answered so well with the former agent, might be employed in the same manner, and used successfully with the latter agent. Vapour of chloroform, when inhaled of twice the proper strength, i. e., of 8 or 10 per cent., is capable of causing sudden death by over-narcotism of the heart; but amylene is required to be of nearly 40 per cent., or more than twice the proper strength, before it could produce this result: and it seemed, therefore, reasonable to expect that the inhaler which had been employed for so many years with chloroform, might be employed in exhibiting amylene with an equally satisfactory result. And if the amylene furnished for inhalation had been a constant and uniform product, boiling steadily at the same temperature, like chloroform, there is no doubt that these expectations would have been fulfilled.

I first administered amylene, in King’s College Hospital, on the 10th of November 1856, to two boys, about fourteen years old, previous to Mr. Samuel Cartwright extracting some teeth. I had but a few drachms, and being very sparing of its use, it did not entirely remove consciousness in either case, and the pain was not altogether prevented: the effects, however, as far as they extended, were so favourable as to encourage a further trial, which was made in the same institution, on December 4.

On this occasion I exhibited the amylene to four patients—two men, a young woman, and a girl of ten years old: it occasioned complete unconsciousness and absence of pain in each case. The first man was about thirty-five years of age. Half a fluid ounce of amylene was put into the inhaler, and he inhaled for three minutes. At first the valve of the face-piece was about one-third open, but it was gradually moved till it was almost closed. The man breathed readily, without coughing, and in a very little time seemed to be unconscious. The pulse became quick and slightly irregular; the skin became flushed; and in about two minutes there was a rather free sweating of the forehead; the eyes did not turn upwards; the conjunctivæ did not become insensible; there was no relaxation of the limbs, and, on the contrary, no struggling. The patient sat well, supporting himself, without any tendency to slide out of the chair; the mouth was partly open, and there was a tendency to laugh, just as the amylene was discontinued. The tooth was extracted by Mr. S. Cartwright, without making him flinch or cry in the least. In less than a minute he awoke. He looked a little strange at first, but immediately remembered all the circumstances of his situation, but knew nothing of the operation; and, three minutes after the extraction of the tooth, and six minutes after entering the room, he went away feeling, as he said, quite well. The amylene put into the inhaler was nearly used.

A young man, about twenty years old, next inhaled the same quantity, in exactly the same manner, for just three minutes; there was no irregularity of pulse, and no sweating; otherwise the symptoms were exactly the same. The tooth was extracted without his knowledge, and without causing a cry or flinch. He awoke, and was able to go in three minutes.

A young woman in bad health, an out-patient of one of the physicians of the hospital, next inhaled. She breathed the amylene for four minutes, and about three drachms were used. The effect was carried to the commencement of the third degree of narcotism; and the eyes were inclined to turn up, but did not do so persistently. The edges of the eyelids also remained sensible. There was a little trouble and delay in getting the mouth open, as the muscles of the jaws were rather rigid; and when the tooth was extracted, she flinched, and cried out a little. She did not remember the operation. She said she had had a very unpleasant dream, and she was dizzy and uncomfortable for about ten minutes, after which she was better.

A little girl ten years old inhaled for four minutes, and between two and three drachms were used. The eyes were turned up for a short time. She did not flinch or cry as the first tooth came out, but did both as two others were afterwards extracted. She did not, however, know anything afterwards of the operation. She recovered her consciousness in a minute or two, and quite recovered from the effects of the vapour in a few more minutes. There was no sickness, and no increased flow of saliva, in any of the cases.

On December 11th, I administered the amylene again in five more cases of tooth-drawing, with very similar results to those obtained in the previous cases; and on December 13th, I exhibited it in some more important cases.

Mr. Fergusson performed an operation for fungus of the testicle; Mr. Bowman removed some diseased glands from the groin; and there were two cases of tenotomy, in one of which forcible extension of the knee was made.

From November 1856 to July 1857, I exhibited amylene in 238 cases. There were seven cases of lithotomy; six of the patients were children, and the seventh a young man of seventeen. They all recovered. Five of the operations were performed by Mr. Fergusson, in King’s College Hospital; and two were performed in St. George’s Hospital, by Mr. H. C. Johnson and Mr. George Pollock.

There were five cases of resection of the knee; three of the patients got well, and two died. These operations were performed in King’s College Hospital, one of them by Mr. Partridge, and the other four by Mr. Fergusson. Of the seventeen cases of resection of the knee, mentioned at page 280, in which chloroform was administered, I know the result only in thirteen of the cases. Of these, eight recovered, one of them after undergoing subsequent amputation at the thigh; and five died.

Some statistics of this operation have been gathered by collecting the cases which happen to be reported in the medical journals, but such statistics are likely to be extremely erroneous. The cases that are reported are probably far more favourable than those that are not reported. A surgeon undertakes an operation of this kind with no other view than the benefit of his patient, and without thinking of the medical journals; and, if his first or second case is unsuccessful, he is probably not inclined to repeat the operation. If the cases should be successful, however, he is inclined to repeat the operation when opportunity occurs, and may ultimately give the result of his experience to the profession.

Mr. Bowman removed the head of the femur in two little boys to whom I administered amylene; they both recovered, as did a girl who inhaled amylene whilst Mr. Fergusson performed resection of the elbow. I administered amylene in four cases of amputation of the thigh: one of these operations was performed by Mr. Henry Lee, on January 7th, 1857, on a girl aged twelve or thirteen, who underwent resection of the knee on the 1st of November previously. That operation was performed by Mr. Bowman, and the girl inhaled chloroform. At the time of the amputation, she was suffering from pyæmia, was extremely weak, and had a pulse of 150 in the minute. The vapour was exhibited to the patient in bed, before her removal to the operating table. There was an examination of the knee before the operation; and the anæsthesia was kept up till the dressings were applied, which was twenty-five minutes from its commencement, and nearly three fluid ounces of amylene were used. She went through the operation extremely well. There was no sign of pain, and the pulse remained the same throughout the operation, and there was no depression. The patient recovered.

There was one operation of amputation below the knee by Mr. Fergusson, in which I administered amylene. The patient was a woman of twenty. The operation was performed on account of paralysis of the muscles of the leg and foot. She recovered. There was an amputation of the forearm; two amputations of the great toe, with its metatarsal bone; and two or three of toes and fingers: four cases of operation for stricture of the urethra by perinæal section—three of them by Mr. Fergusson, and one by Mr. Curling. There were three operations of lithotrity, two for hæmorrhoids and prolapsus ani, and four for fistula in ano. There were nine operations for the removal of tumours of the female breast; there were seventeen operations for necrosis of the tibia, femur, lower jaw, and other bones.

I administered amylene in several operations on the eye. There were two operations for cataract by extraction, and one by drilling, performed by Mr. Bowman; eight cases of excision of the eye by that surgeon, as well as some operations for artificial pupil, for the removal of foreign bodies from the eye, for staphyloma, and one for the separation of the eyelids from the globe. There were also twelve operations for strabismus, eleven of them by Mr. Bowman, and one by Mr. Fergusson.

I exhibited amylene in forty-eight operations of tenotomy. Several of them were performed by Mr. Fergusson, but the greater number were performed by Mr. W. Adams and the late Mr. Lonsdale, in the Orthopædic Hospital. The narcotism was scarcely carried beyond the second degree in any of these cases. The eyes were open, and the features generally had an expression as if the mind was active on some subject or other. The muscles were nearly always in a state of tension, at least they were not relaxed in any case. Many of the patients were children, and a number of them only inhaled between one and two minutes. There were five operations for the forcible extension of stiff joints, and two for dislocation of the humerus: the latter were treated in the St. James’s Parochial Infirmary. The first case was a dislocation downwards in a woman aged sixty-eight. She inhaled for three minutes, when, extension being made, the bone slipped into its place with the utmost ease, although Mr. French had found a good deal of resistance in an attempt he made just before sending to me—not any serious resistance or pain, but so much of both as led him to think it would be a good opportunity for trying the amylene. In two minutes after the reduction of the dislocation, and five minutes after beginning to inhale, the patient was quite awake again, and said that she had felt nothing. The other case was a dislocation forwards in a man aged seventy-two. No attempt to reduce it was made till the amylene was administered. The case was under the care of Mr. Buzzard. After inhaling two or three minutes, the old man got into a state of muscular rigidity, and did not get beyond this state, although I continued the inhalation nearly ten minutes, until about two ounces of amylene were used. He was quite insensible, but the rigidity prevented the reduction of the dislocation. So I discontinued it, and sent for some chloroform, which I administered a few minutes afterwards. It produced muscular rigidity rather stronger than that which the amylene had caused; but, by continuing the inhalation steadily for about two minutes, the limbs became relaxed, and the humerus slipped easily into its place. This is the only case in which the amylene has not effected the purpose for which I have exhibited it; and I have no doubt that I could have produced relaxation of the voluntary muscles by increasing the strength of the vapour the patient was breathing; for I have always been able to produce relaxation of the muscular system of animals with it; but there were one or two circumstances which at the moment stood in the way of this. The patient’s face was so hollow from his loss of teeth that the face-piece fitted badly; and, as it was early in a frosty morning, the water-bath of the inhaler was colder than usual. These defects could have been remedied if necessary, but I thought it as well to use chloroform; and I am inclined to think that chloroform and ether are better agents to employ in those instances where relaxation of the voluntary muscular system is required.

Sixteen tumours of different kinds were removed from different parts of the body, in addition to the tumours of the breast previously mentioned, in cases in which I administered amylene; and there was also a number of miscellaneous operations which I have not mentioned.

One of the patients of the late Mr. Lonsdale at the Orthopædic Hospital was a girl of seventeen, who had the scapula drawn up in an extraordinary manner by the action of the muscles. When she became unconscious from the amylene the shoulder came into its right position, with hardly any pressure, although her muscular system was not in the least relaxed from the action of the vapour; and the deformity remained absent for three days. The amylene was repeated three or four times with the same temporary benefit, and chloroform was given on one occasion when I was not present with a similar result. I have not heard of the subsequent progress of the case. I cannot suppose that the direct effect of amylene would remain three days on the nervous system, and I conclude that the result was brought about by some change in the emotions of the patient.

I gave amylene in twenty-four cases of tooth-drawing, including those which were previously mentioned. One of the cases was that of a lady under the care of Dr. Oldham. She was suffering from a large ovarian tumour, and was unable to rise from the sofa. Mr. Bell extracted four teeth whilst she was under the influence of the amylene. She became insensible without the least excitement, was perfectly quiet during the operation, and recovered in a minute or two, feeling quite cheerful and well.

I have administered amylene in seven cases of labour. The first patient was under the care of Mr. Buzzard in St. James’s Infirmary, on January 20th, 1857. It was the patient’s second labour, and was a lingering one, having lasted thirty-five hours. I administered the amylene only during the last twenty minutes preceding the birth of the child, the head being advanced so as to rest on the perinæum. The vapour was given, well diluted, at the beginning of each pain. The patient breathed very deeply, and got relief very quickly from each pain; the mind was quite clear between the pains, and I could not tell whether or not the consciousness was removed for half a minute or so during each pain. Half a fluid ounce of amylene was used. The next case occurred in an out-patient of King’s College Hospital, under the care of Mr. Meadows, Dr. Farre’s assistant. It was the patient’s third confinement. I arrived three hours after the commencement of labour, and two hours before the birth of the child. The os uteri was almost dilated on my arrival, and the pains were very strong, recurring every three minutes or so. They continued to increase in strength to the last. The patient was probably unconscious for a brief period during the uterine contractions, while the amylene was administered, but between the pains she was quite conscious. Under the use of chloroform, in a labour with brisk and frequently recurring pains, as in this case, the patient usually sleeps on from one pain to another. The amount of amylene inhaled in this case was three fluid ounces. The quantity used in each of these cases must have been about half a fluid drachm in each pain, and this is the quantity I had previously recommended Dr. Tyler Smith to employ, when he did me the honour to ask me some questions about amylene before he employed it in a case of labour. The results arrived at by Dr. Tyler Smith, in a case in which he employed amylene, were similar to my own, viz. relief of suffering during the uterine contraction, consciousness between the pains, and no interference with the progress of the labour.

On April 28, 1857, I administered amylene in Brownlow Street, Drury Lane, to a woman in her sixth labour, attended by Mr. Ponsonby R. Adair, one of Dr. Farre’s assistants. She had been in labour since three P.M. the previous day. The os uteri was fully dilated, and the amylene was commenced at 5·25 A.M., and continued till 5·50, when the child was born. The placenta was expelled in a few minutes with very little bleeding. The amylene was exhibited with the inhaler at the beginning of each pain, which it soon relieved, although the patient did not become unconscious. The pains came on every two minutes or so, and kept increasing in force till the birth. About six drachms of amylene were used.

On May 1st., I administered amylene to another woman in her sixth labour, also attended by Mr. Adair. The vapour was commenced at 9·30 P.M., the patient having been in labour a few hours. The os uteri was not fully dilated. The pains came on regularly every three minutes, but were not very strong; they, however, gradually increased, and the child was born at half-past eleven. The cord was round the neck, and the child was nearly asphyxiated in the birth, but it was restored readily by Dr. Marshall Hall’s method. The placenta was expelled a few minutes after the child with very little hæmorrhage. The patient inhaled with every pain, which was very quickly relieved. The last quarter of an hour, she seemed to be altogether unconscious. About three fluid ounces of amylene were used.

On May 14th, I exhibited amylene for about an hour to a woman in her third labour, attended by Mr. Adair. The os uteri was nearly dilated when I arrived, and the patient had been in labour about ten hours. The pains occurred every three or four minutes, but were not strong. Amylene was inhaled with each pain for about an hour, when the pains almost ceased, just as the os uteri was fully dilated. I waited for half an hour without giving amylene, and then left to attend to another engagement. Mr. Adair informed me that the pains returned soon after I left, and that the child was born in about half an hour. The patient was hardly rendered unconscious by the amylene. Between two and three fluid ounces were used.

I exhibited amylene for an hour and ten minutes, on May 25th, to a woman aged 20, in her first labour. She was attended by Mr. Adair. She had been in labour since three P.M. the previous day, and the os uteri was not fully dilated. The amylene was commenced at 9·30 A.M., and inhaled with each pain, which it relieved in a very manifest way. The pains recurred every two minutes and a half. I left off giving the amylene at 10·40 to attend to other business. Mr. Adair informed me that the labour was concluded at one P.M.

On July 1st, I exhibited amylene to a woman in labour with her third or fourth child. Labour commenced at midnight of June 27th, and continued during the following day till the os uteri was dilated to the size of a crown piece, when the pains subsided on the evening of that day, and did not return to be effectual till the evening of July 1st. The amylene was commenced at 10·25, the os uteri being almost dilated, and the pains recurring every three or four minutes. The uterine contractions increased in force and frequency, and the child was born at 11·45. There was a gush of blood two or three minutes after the birth of the child, and Mr. Adair introduced his hand and removed the placenta, which was only partially detached. The hæmorrage immediately ceased. The patient was feeble and emaciated, and had suffered repeated beatings by her drunken husband. She recovered favourably, as did the other patients.

The action of the amylene was very favourable in these obstetric cases. The pains were relieved very promptly by it, generally by the time the patient had taken two or three inspirations, and the effect of the vapour passed off in most cases between each pain.

The great ease with which amylene can be breathed, owing to its entire want of pungency, is a decided advantage which it possesses over both ether and chloroform. Insensibility can always be induced with amylene in as short a time as is desirable, namely, in from three to four minutes in the adult, and about two minutes in young children. It is not desirable to cause insensibility in a shorter time than this with any agent. If narcotism is induced too quickly, the symptoms are not uniform or in regular order, owing, no doubt, to the circumstance that the narcotic vapour is not equally distributed through the blood, which must convey it to the nervous centres. Insensibility can, indeed, be generally induced with chloroform in the time above mentioned, but there are many cases in which there is considerable delay at the commencement of inhalation, owing to the pungency of the vapour, especially in nervous and in sensitive patients, and in persons with irritability of the air-passages from chronic bronchitis, phthisis, or any other cause.

In the use of amylene, absence of pain has been obtained with less profound coma than usually accompanies the employment of chloroform and ether. There are some cases, indeed, in which the minor parts of an operation, under these latter agents, may be performed without pain while the patient is in a semi-conscious state, or even altogether conscious, but they form an exception; while in the use of amylene, the patient has very often been half-conscious during the operation. In operations under chloroform, the patients usually indicate the necessity of repeating the inhalation by a tendency to flinch or cry, without showing any signs of consciousness; but in the use of amylene, they have more frequently begun to look about and to speak before showing any sign of pain. There are some patients who will not lie still under the surgeon’s knife while chloroform is being used, unless its effects are carried so far that the breathing is on the borders of being stertorous, but I have not met with any such case in using amylene.

The greater number of the operations under amylene were performed while the patient was in the second degree of narcotism, being apparently awake, although not really conscious of surrounding objects. This usual absence of coma in the employment of amylene cannot be looked on otherwise than as an advantage. It must conduce to the safety of the agent when the proportion of vapour in the air is properly regulated. The reason why no accident is known to have happened from chloroform, in the practice of midwifery, when superintended by a medical man, is no doubt due to the circumstance that it is only requisite to induce a slight effect, in comparison with the effect required in surgical operations.

The best indication that the patient will quietly bear an operation under chloroform, is the more or less complete absence of sensibility of the ciliary edge of the eyelid; but during the inhalation of amylene the patient is often entirely regardless of the surgeon’s knife, whilst the edges of the eyelids retain their full sensibility, and the slightest touch causes strong winking. In operations on the eye, however, and in all other cases where great steadiness on the part of the patient is required, I have thought it best to continue the amylene till the sensibility of the margin of the eyelids was almost abolished; and to effect this it has usually been requisite to carry the influence of the vapour as far as the beginning of the third degree of narcotism, or that condition in which there is no longer voluntary motion of the eyes, or any other part, and in which the eyelids are usually closed, and the pupils inclined upwards. But even in these cases the patient has usually reverted to the second degree of narcotism before the end of the operation, and has shown signs of ideas by the voluntary motion of the eyes and eyelids, or in some cases by speaking. In several cases, however, the sensibility of the eyelid has been removed in the second degree of narcotism; and important operations have been commenced before the patient was “off”, to use an expression familiar on these occasions. One instance of this kind was the operation of lithotomy by Mr. Fergusson, on the 14th of March, 1857, in a young man, aged 17, in King’s College Hospital. The sound was first introduced, and the stone being detected, the assistants were requested to tie the patient up; and finding his limbs somewhat rigid, they requested me to give him some more vapour. If I had been using chloroform I should have done so without any request, in order to cause relaxation; but I allowed the effect of the amylene to partially subside, and in less than a minute the bandages could be easily applied. I then proceeded to give a little more amylene, but soon found that the margin of the eyelids was insensible; so the operation was performed whilst he was calmly looking about, as if awake; but he showed no sign of pain, and knew nothing of the operation. I never saw a capital operation performed on the adult, under the influence of chloroform or ether, whilst the patient was in this condition; but I once administered chloroform in St. George’s Hospital to a child of three or four years old, which was cut for stone whilst lying calmly with its eyes open, and holding a toy in its hand, all the time of the operation, without letting it fall.

The pulse is almost always increased in frequency and force during the inhalation of amylene,—especially during the early part of the inhalation, and to a greater extent than happens with chloroform. The respiration is very often accelerated during the inhalation,—about as often, I think, as with ether, and more frequently than with chloroform. In many of the early cases in which I administered amylene, the pupil was dilated for a short time; but I consider that this arose from giving the vapour rather stronger than is desirable. I afterwards gave it more gently, and very seldom observed the pupils to be dilated. They remained, as nearly as I could tell, of the natural size, and also sensible to light, in the cases where I made an observation on that point.

The colour of the countenance is generally heightened more or less during the whole period of the inhalation, and in a few cases there was sweating,—a symptom met with now and then under the influence of chloroform and ether. Amylene does not cause the great increase in the flow of saliva which is so often met with during the inhalation of chloroform, and especially of ether.

There is a tendency to laugh during the inhalation of amylene much more frequently than during the use of chloroform. It occurs just after the patient has lost his consciousness, but is soon subdued by the increasing effect of the vapour. I only met with strong mental excitement in a very few patients, chiefly females. It subsided in half a minute in one case, on leaving off the vapour, and did not recur when the inhalation was resumed. In the other cases it was subdued by continuing the inhalation.

The expression of the countenance generally remains calm and cheerful during the action of amylene; but in a few instances there is a singular, and even unpleasant, aspect of the face for a short time, arising apparently from a brief spasmodic action of the muscles.

I met with less rigidity and struggling during the administration of amylene than in the use of chloroform; but this probably arose from the circumstance that the effects of amylene were very frequently not carried to that degree in which rigidity and struggling are liable to appear. It is in the third degree of narcotism from narcotic vapours that rigidity is met with in those cases in which it occurs, but the greater number of the operations under amylene were performed in the second degree of narcotism. The rigidity from amylene, when it occurs, is of a somewhat different kind, and takes place in patients in whom we should not expect it from chloroform. In the spasm and rigidity from the latter agent, the head is more commonly bent forwards or turned to one side, although it is occasionally thrown back; but under amylene, the latter is the usual position it assumes when rigidity occurs, constituting a brief opisthotonos. The rigidity under the influence of chloroform is usually accompanied with struggling, while in that caused by amylene the patient is generally quieter. The persons in whom rigidity and struggling are most violent from the effects of chloroform are lean, muscular men, who work at hard labour, or follow athletic sports, such as hunting, and especially boating; while those who lead a sedentary life, or are reduced by illness, seldom exhibit these phenomena. Women and children seldom exhibit any rigidity under chloroform, and fat persons least of all. Old people do sometimes, especially if thin. Under the use of amylene, on the other hand, I have most frequently met with some amount of rigidity in children and young persons, while many robust men, in whom it would be almost certain to occur under chloroform, have not shown any signs of it. The cause of this probably is, that the operation has generally been performed without carrying the narcotism beyond the second degree, while rigidity does not take place till the third degree is attained. In every case where rigidity and struggling have occurred in the employment of chloroform, however violent these symptoms might be, I have continued the vapour gently and steadily till they were subdued, either by removing the tendency to these symptoms, or by carrying the narcotism to the fourth degree, which is accompanied by relaxation of the voluntary muscular system, and usually with some tendency to stertor. In the use of amylene, on the contrary, I have not attempted to subdue the spasm by continuing the inhalation, but have, with the exception of a case of dislocation previously mentioned, withdrawn the vapour when the rigidity appeared, and the operation has either been performed at once, or else, if it was of a nature that the spasm would interfere with, I have waited a short time, and exhibited a little more vapour very gently, so as to get a state of anæsthesia without the recurrence of the spasm.

Mr. Jones, of Jersey, favoured me with the following account of a case in which amylene acted much more favourably on his patient than chloroform.

John D., æt. 41, stout and of very ruddy complexion, so injured his leg that it was deemed advisable to saw off the fractured ends of the tibia. Chloroform was at first given (March 16, 1857), but the effect it produced, though administered with the utmost caution, was evidently of so dangerous a nature, that it is more than probable that death would have resulted had it been persevered in longer than five or six minutes (the period it was employed). The patient became quite apoplectic, and had two or three very severe convulsions. Amylene was at once substituted, and with the happiest result. The patient appeared conscious, but was not so, and the operation, which was a tedious one, was commenced and finished without his experiencing the least pain, indeed without his having the slightest knowledge that operative measures had been resorted to.

Amylene differs widely from chloroform, and still more from sulphuric ether, in the promptitude with which patients generally recover from its effects. This is a character of amylene which might have been predicted from its physical properties. I have many times observed how quickly, and, indeed, almost instantaneously, small animals recover from the stupor occasioned by certain permanent gases which are sparingly soluble in watery fluids, as olefiant gas, carbonic oxide and carbonic acid gases, nitrous oxide and the gaseous oxide of methyle. Now amylene is so volatile as to approach to a permanent gas; at a temperature a little above that of the human body it would be a gas, and the vapour is very sparingly soluble in watery fluids, and consequently in the blood. Sulphuric ether is, indeed, as volatile as amylene. I cannot remember any other two bodies whose volatility is so nearly alike; but sulphuric ether is very soluble in watery fluids, in comparison with amylene. Water dissolves a tenth of its volume of liquid ether, or 23 volumes of the vapour. Consequently a large quantity of ether is absorbed during inhalation, and the blood has to pass many times through the lungs before it is freed from it. The quantity of amylene which is absorbed is, on the contrary, extremely small, as I have explained above, and this, together with its volatility, is no doubt the reason why the patient recovers so promptly from its influence. In about a minute after the operation is concluded, and the inhalation left off, the patient usually awakes from the influence of amylene, and completely recovers his consciousness. The same quick recovery may take place after chloroform, but more frequently it is a few minutes before the patient is quite conscious. I have seen two or three instances in which a child has slept for twenty minutes or half an hour after amylene, but it must be remembered that children sometimes sleep for hours after chloroform in cases where the operation has not produced a painful wound. The quick recovery of the patient is a decided advantage in all minor operations. In great operations, where the patient is obliged to keep his bed afterwards, it is of less consequence whether he wakes promptly or not, although, even under these circumstances, his friends are generally anxious to see him recover his consciousness. The smarting of the wound after an operation is often prevented longer when chloroform has been employed than after the use of amylene, and this may be considered as a slight advantage which chloroform possesses in certain cases. In some instances, however, in which chloroform has been used, the patient begins to show symptoms of suffering pain in the wound before he has entirely recovered his consciousness, while after amylene I have not seen symptoms of pain in the wound till consciousness had completely returned. In any cases where the pain after an operation, either from a wound or ligatures or caustic, is very great, the inhalation of the agent which has been employed may be gently repeated at times until the pain has a tendency to subside, or till an opiate shall take effect.

The patient generally seems surprised or confused on first recovering from the effects of the amylene, but in a few seconds he becomes, in most cases, completely conscious of his position, and feels that his mind has been wandering. He often says he does not know where he has been in his dreams, or that he has been a long way. Sometimes he does not remember exactly what he has dreamed about; at other times he does. All this is common enough after chloroform, except that the process of recovery is generally much slower; but there is one condition of mind which is very common after chloroform, which I have rarely met after amylene, I allude to that condition in which the patient asserts that the vapour has not taken effect, and that he has not been asleep at all.

Amylene appears to support the pulse under loss of blood at least as well as chloroform. I have not found the pulse to fail, although there was rather free hæmorrhage in some of the operations.

There has been a little headache in a few of the cases as the effects of this agent were subsiding, but it passed off in a few minutes.

In administering amylene, the vapour must be given of such a strength as will cause insensibility in about three minutes, or it will not succeed at all unless the strength of the vapour be altered. In giving chloroform, the vapour may be of less than half the desirable strength, and by continuing more than twice the usual time, the patient may be rendered insensible; and in using sulphuric ether, the vapour may be breathed of one-seventh the proper strength, and by continuing it constantly for seven times the usual period, i. e., for half an hour, the patient might be rendered insensible; but in using amylene, time will not make up for deficiency in the strength of the vapour. If the vapour be not strong enough to cause insensibility in about three minutes, it might be breathed for an indefinite period without causing insensibility; and the patient is solely affected by what he has inhaled within two or three minutes.

On account of the very rapid subsidence of the effects of amylene, it requires to be very frequently repeated during the performance of an operation. The patient generally requires to inhale a little of it every half minute or so to keep up its effect. On this account, it is not well adapted for certain operations on the face. I did, however, administer it with complete success in several operations on the face in King’s College Hospital. Amongst these, there were four operations by Mr. Fergusson for making a new nose in which I administered amylene, and succeeded in preventing the pain by holding a hollow sponge, wetted with that agent frequently, near the mouth and nose.

In cases of tooth-drawing, in which a number of teeth or stumps have to be taken out, the effects of the amylene are apt to pass off before the operation is completed, and the inhalation has to be repeated once or twice, but in cases when only one or two teeth require to be extracted, amylene has a great advantage in the promptitude with which the patient recovers from its effects. There is occasionally some difficulty in opening the mouth with amylene, as with chloroform.

The patient has nearly always a very cheerful expression of countenance when he recovers from the amylene, and the state of his mind, as indicated by his conversation, corresponds to his look. Dr. Debout has noticed the same circumstances. Speaking of the patients operated on under amylene in Paris, he says, “A leur réveil et le premier moment de stupeur passé, leur physionomie est épanouie.” The same state of countenance and mind is met with after chloroform only now and then, and is by no means the rule.

Hysterical symptoms occurred in a few women after operations under amylene. They were met with about as frequently, I think, as after chloroform. These symptoms generally subsided in a few minutes; but in one or two young women in the hospital, they lasted nearly an hour.

The greatest advantage that amylene possesses over ether and chloroform, is the great infrequency with which it excites sickness. I only saw vomiting occur in two of the 238 cases in which I administered amylene, although it occurred before I left the patients’ room in twenty-two cases out of 100 in which I administered chloroform and kept an account of this symptom, at the time I was using amylene. In the greater number of the cases in which chloroform was exhibited, the patients had been requested not to take a meal; whilst in the cases in which amylene was administered, no directions regarding diet had as a general rule been given.

I made subsequent inquiries respecting most of the patients who inhaled amylene, and I was only able to hear of sickness in eight or ten cases, and it was not distressing or troublesome in any of these. It generally occurred three or four hours after the amylene, and subsequently to the patient taking his first meal after the inhalation. In one of the two cases in which vomiting occurred after amylene before I left the room, there was retching for four hours; but I did not hear of so much sickness after any other case in which I administered this agent; and there was no faintness or depression either in this case or any other in which amylene was employed, although faintness and depression often accompany the sickness which is occasioned by chloroform. Some of the patients who inhaled amylene without being sick, had previously suffered from sickness after inhaling chloroform. I administered amylene, on January 30th, 1857, to a lady, about twenty-five, whilst Mr. Bowman operated for strabismus, and there was no vomiting or sickness, either at the time of the operation or afterwards; but the same patient had undergone a similar operation a week previously, when chloroform was administered, and on that occasion vomiting commenced before the operation was finished, and recurred every quarter of an hour, with violent retching, for twelve hours.

I had the misfortune to lose two patients from the inhalation of amylene. The following are the particulars of these cases.

Mr. Fergusson requested me to assist him on the 7th of April, 1857, in the case of a gentleman on whom he was about to operate for fistula in ano. The patient was thirty-three years of age, and was in good health, with the exception of the local complaint, although he had lived somewhat freely. Mr. Fergusson examined the patient’s chest the day before the operation, and found the sounds of the heart to be normal. I felt his pulse just before he began to inhale. It was natural, but somewhat accelerated, as usually happens just before an operation. He was lying on his side in bed. About six fluid drachms of amylene were put into the inhaler (I never intentionally used all I put in, but added more before the paper became dry), and he breathed steadily and gently. The valve was gradually advanced over the opening in the face-piece till it about three-quarters covered it, and the patient appeared to become quietly unconscious in about two minutes. He breathed quickly for a few inspirations just as he appeared to become unconscious. Just after this, Mr. Fergusson came and felt the patient’s pulse, and he says it was very good. I felt it also. I looked at my watch at this time, and it was two minutes and a half or two and three-quarters from the beginning of the inhalation. Mr. Fergusson commenced to use the probe, and, finding the patient did not flinch, he began to use the bistoury. Mr. P. C. Price assisted at the operation. I held the patient’s thigh with one hand, as I often do in such an operation, lest he should flinch. He did not flinch, however, but kept his limbs tense, without moving them. Just at this moment, I observed that the valve of the face-piece, which I had left three-quarters covering the opening, had moved so as to cover it entirely, but I cannot say whether or not the patient had taken an inspiration a little stronger than I intended, and thought nothing of the matter, as I have frequently had to close the valve completely in giving amylene. It could not, however, have been many seconds in that position, for I paid no attention to the operation, except so much as was requisite to guide me in what I was doing. The inhalation was discontinued at the moment I have mentioned, and on looking round directly after, I found that the operation, which had apparently been but one incision, was finished. I now began to feel for the pulse, more out of constant habit, and from a scientific curiosity, than from any supposed necessity of doing so. Although it had been good only half a minute before, I could not find it in the left wrist, and only a slight flutter in the right one. His breathing was, however, good, indeed quite natural, and he did not seem even to be very insensible, for there was some motion both of his features and limbs, as if he were about to awake. I watched the patient with great anxiety, thinking that surely his good and natural breathing would restore the pulse, and feeling that at all events this superseded any other measures at the moment. In two or three minutes, however, he seemed to be getting more insensible; he did not wink on the edge of the eyelids being touched, and the breathing was getting slower and deeper. I called Mr. Fergusson’s attention to the patient, and both he, who was preparing to go away, and Mr. Price, who had all the time been standing by the patient, were surprised to find that anything could be wrong, as they had seen the patient going on apparently so well, not only during the inhalation, but after it was discontinued. They dashed cold water in his face, which did not seem to have any effect. His countenance was now livid, and his breathing of a gasping character. It soon began to leave off, with the exception of deep, distant, gasping inspirations, and we therefore began to perform artificial respiration, by Dr. Marshall Hall’s method, placing him in the prone position, and bringing him partly round, while Mr. Price kept the mouth open. The air could be distinctly heard passing through the larynx during this motion. We also tried pressing on the chest with the head on one side and the mouth open, which answered very well as regarded the ingress and egress of air. Inflation from mouth to mouth was tried, but did not seem to answer so well. Although deep gasping inspirations were made by the patient till fully ten minutes had elapsed from the failure of the pulse, the measures used had no effect; I believe that I heard a feeble motion of the heart even after this period; and, as Mr. Fergusson perceived a slight pulsation at the same time in the right wrist, I was probably not mistaken. There were no further signs of life after this, although the artificial respiration was continued for a long time. I am quite sure as to the length of time respiration continued after the failure of the heart’s action. The pulse ceased to be distinctly perceptible at ten minutes before five, and the patient was still breathing at five o’clock. He had not taken food for some hours, but drank a pint bottle of ale a little while before the operation. A good portion of amylene remained in the inhaler after it had been uncovered for an hour and a half.