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.
A 64
B 91
C 75
D 69
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.
Temp. Fah. Vapour. Air.
24° 20·3 79·7
26 20·9 79·1
28 21·6 78·4
30 22·3 77·7
32 23·2 76·8
34 24·3 75·7
36 25·5 74·5
38 26·8 73·2
40 28·2 71·8
42 29·6 70·4
44 31·1 68·9
46 32·7 67·3
48 34·3 65·7
50 36·0 64·0
51 36·9 63·1
53 38·6 61·4
55 40·0 60·0
57 42·5 57·5
58 43·7 56·3
59 45·0 55·0
60 46·5 53·5
61 47·7 52·3
63 50·4 49·6
65 53·1 46·9
67 55·9 44·1
69 58·8 41·2
71 61·9 38·1
73 65·1 34·9
75 68·6 31·4
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.