Experiments
on Animal Electricity
made
in May on the days 20, 21, 22, 23, the weather being cool and dry.
1. A frog, with the full discharge of a 16 sq. in. bottle running from the head to the extremity of
one foot, fell into asphyxia, but a short time later it recovered. The night between the 20thand the 21st, around 12 p.m., with repeated discharges it finally appeared dead, and in fact the following morning I found it dead at about eight a.m. Nonetheless, in its hind legs convulsions were excited by even the slightest spark on the first conductor, and also by discharges of a small bottle producing no spark.
Finally, at twelve o'clock, this dead frog having been prepared the usual way, and the needle having been thrust into its spinal marrow, the frog showed
it was sensitive to the electricity from a simple conductor three feet long, charged to 3 degrees on the micro electrometer---that is, provided that the electric fluid be directed from the nerves to the muscles, for otherwise, in the opposite sense, as usual 12 to 14 degrees were required. After having had the nerves armed(*) in the usual fashion, it gave sufficiently strong signs of its own spontaneous animal electricity with the application of a simple
conducting arc, etc.
Hence, this frog
was still quite full of vitality. Its muscles here and there were largely speckled with a livid red
colour, but there also were pale, sound portions.
2. Another frog was asphyxiated twice or thrice, and finally killed (towards midday on the 21st) with the lightning from a 96 sq. in. bottle charged
right up to as many as 60 degrees on the Quadrant electrometer. It was then no longer affected either by the small sparks or by the stronger electric
strokes, either intact or prepared as it was a short time later. Much less could be
seen any signs of innate animal electricity, which showed itself to be rather extinguished. The muscles, exposed meanwhile, appeared
generally inflamed and all were coloured a shade of crimson tending to violet, whereas those of frogs, live or dead but not killed instantaneously by the electric lightning, appear pale and
white.
3. Another frog received a few shocks measuring 40 to 45 degrees of charge
from the same large flask and it finally appeared to be dead in its hind legs. Thus dead it remained for several hours; however, in its front legs one
could still observed some small motion. [The frog of the previous exp. had been given shocks even through the front legs, whereby life and vitality had both been thus extinguished. It is also to be noted that, if the discharge is given from the head to one of the hind legs, only this one seems to die, the other one continuing to move
albeit feebly. Therefore, one ought to give a discharge through this one as well. It is best to let a discharge pass from the right front leg to the left hind leg and another one from the left front leg to the right hind leg, whereby
all four legs are deprived of life and motion with only two strokes, if they are strong enough.]
Now,
even this fine, intact frog was affected by the tests of even weak artificial electricity, and even the muscles of the dead legs contracted.
Greater still was the effect when the frog was prepared as usual, almost as if it had been prepared alive and sound, only in the larger muscles of the thighs, though, which appeared not so inflamed as the others nor dark red
like those of the of the frog of the previous exp. Thus one could see only the sound parts palpitating and shaking. Neither in these did the spontaneous animal electricity fail to manifest itself (once the nerves had been armed in the customary manner and the conducting arc was applied as
usual).
4. A frog was beheaded towards midday on the 22nd, and I thrust a big needle into its marrow, at which point it stretched
out violently and died. Thus dead it remained wrapped in a small cloth until the following day, 23rd; tested as it was towards 10 in the morning, the spark of the usual conductor charged to 15 degrees of the Elec. Quad. excited in it some very small convulsions;
with 20 degrees of elec. both legs shook considerably. At 25 and 30 degrees, the convulsions were stronger, but not by much.
With the flask with a 16 in. armature, a charge measuring 12 to 14 degrees on the micr. elec. was enough; one of 20 made one of the legs, which was hanging down, oscillate like a pendulum.
Having hung the frog by the feet, one here and one there, the trunk hanging down, again the charge of 12 degrees of the micr. elec. was enough to make the muscles of the thigh visibly
contract and the trunk swing. 10 degrees did not suffice, then 5 on the Quadr. elec.. excited such a shudder that the small bottles which supported it shook together with the frog. With the four
foot conductor, 12 degrees on the Quadr. elec. were enough. It thus seemed that the electricity was
so much more effective at contracting the frog’s muscles if the flow was directed from the end of one leg to the end of the other, rather than from the spine to the feet.
Finally, I tested it with the 96 sq. in.
jar charged to 14 degrees on the Quadr. electr., at which point the frog convulsed violently and arched itself, and thus arched and tense it remained, in a state of strong tetanus, for several
seconds.
I tried again with the 16 in.
flask charged to 15 and 20 degrees of the Quadr. el. Strong undulation and shaking but not the
tetanus.
I returned to the big
jar charged to 15 degrees Q. E. Vehement trembling but no tetanus.
Once the frog was finally prepared in
the usual manner, its nerves armed, it did not fail to show signs of its own innate electricity,
feeble and scarce as they were, obeying almost only to the touch of silver, and even this only for a short time Yet,
to the last, it still possessed a residue of that vitality which I shall call electric.
To cause contractions with the artificial electricity of the simple Conductor, 12 degrees of the Qu. elec.
were needed; with the 16 in. bottle, about 20 degrees of the micr. elec., the fluid being directed from nerves to muscles, and about 30 degrees directing it from the latter to the former.
The frog skinned, in its muscles appeared reddish streaks, indicating inflammation, caused, as it seems, by the electric discharges it had undergone before being
prepared.
5. One frog
whose head I chopped off on the 22nd day at noon (a) and which I kept wrapped in a small cloth, was still alive, that is, it moved and made paces 24 hours later. While I was handling it
as it hung by the hind feet on the scaffold, it violently shook itself, and it made climbing motions with its legs, etc. as much as would a whole, sound
frog.
Under tests of artificial electricity, this frog behaved, both whole and prepared, as if its head had not been chopped off 24 hours before.
It also responded but little and with difficulty to tests on its own electricity.
6. I passed the electric
shock from the 96 sq. in. flask, charged to 51 degrees, from one of the front legs to one of the hind legs.
These remained paralysed and as if dead, the other ones still moving. Once the frog was skinned, one saw red streaks in the shocked thigh and leg, but
there were not many of them nor were they deeply coloured, while in the other only a little. Once prepared, only the leg which had not been shocked gave signs of spontaneous, although weak electricity, for it too had suffered, as it showed
by stretching itself at the moment of discharge, and as the few red stains it contracted indicated
clearly(1)
Apr. 24th
Fine weather, dry and windy. Temp. ... deg.
At 11 in the morning I prepared three frogs. The 1st, which gave highly vivacious signs of spontaneous electricity even unarmed,
shuddered for about half of a quarter hour like that, then for another half quarter armed.
It was subsequently exposed out of the window on the bare stone in the dry air: therm. 11 to 12 degrees.
The big , lively 2nd one, having been prepared
at 20 min. past 11, and I observed that it gave vigorous signs without armature.
It was immediately placed in a bucket of water.
The 3rd having been prepared
at 26 min. past 11 in the selfsame manner, and having found that it responded very well unarmed, it was wrapped in a small wet cloth two minutes later.
After having remained thus exposed on the windowsill for 20 min., the 1st
was still playing very well.
The same, or maybe better still after another 20 min.. After another 35 minutes the thighs appeared greatly withered, of a livid reddish yellow
colour, and the nerves dehydrated, at least such were the portions which had been left bare out of the armature;. Nonetheless, the legs still contracted and
leapt at the mere application of the metallic arc.
After ten more mins. the legs, which were more withered, dehydrated and more livid, still moved, opening or closing themselves abruptly with the application of the conducting arc onto them and to the armed nerves, and partial contractions could be observed in the muscular
fibres. In conclusion, its own animal electricity appeared little weakened, and the strong leaps and bounds were absent for no other reason than the
lack of flexibility in the joints and the muscles' almost complete stiffness.
Finally, at the end of 2 hours
after the preparation, and 1¾ hours since exposure on the windowsill, when tested, only a few
fibres in the thighs still palpitated; and a few minutes later, nothing more.
At this point, though, by touching the dry portion of nerves at the
edges of the armature and of the muscles, with wet paper, for the sake of wetting them, there are new contractions and
leg movements, occurring, however, only a few times. Hence, the frog being laid on a wet cloth, one, two more contractions arise, then no more.
Having been taken out after 35
mins. of immersion, the 2nd had some small convulsions or tremors in the muscle fibres, and tested with the conducting arc, it played very well.
After another 35 mins., the thighs appearing white, very white, and the muscles beginning to show signs of maceration with the surface breaking down into filaments, it did not cease to give signs of spontaneous electricity
as before, and almost as strong as before.
After another hour or so, the maceration having progressed and the muscles having become absolutely white, there was no longer any way to obtain signs of spontaneous elec..
Hence, it was exposed, placed as it was on the stone of a window and in the sunlight; after a few minutes, as it had conveniently dried and warmed up a little, it was tested again, but it gave no signs of spontaneous electricity. Yet the legs contracted with artificial electricity, even if weak, that is to say, with the discharge of a small 16 in.
flask at 10 to 12 deg. on the micr. el., this occurring just as much when giving it from the spine to the feet as from one foot to the other.
After
lying for 80 min. in the small wet cloth, the 3rd showed just as vigorous animal electricity as in the beginning.
Another hour later, it convulsed itself with merely picking it up and touching nerves and muscles together abruptly. Tested with the conducting arc, it responded with the usual contractions and
jerks, even with only half the armature of lead foil on the nerves. It was once again wrapped in its wet cloth.
After having been soaked for 7 hours in the cloth, that is at 6.30
p.m., the muscles were very flaccid and so were the nerves. This notwithstanding, once the latter
were armed I had some sign of vitality, i.e. at the touch of the conducting arc some
fibres palpitated in one thigh. This only lasted a few minutes.
Then trying with artif. elect. I found 10 deg.
on the Quad. el. from the simple Conductor were enough to excite convulsions and make a dangling leg swing. Then with the
flask, 10 deg. of charge on the Micr. el. were enough, and 15 conveying the discharge from one foot to the other.
It was
put in the cloth once more and the following morning at 10 it was again tried with the discharge of 20 deg. on the Qu. el. from a 30 in.
jar; after such treatment, some palpitation in a few fibres of the thigh was still to be seen.
After two or three times, 30 deg. Qu. el. were needed. Then it was over.
April 24th
still
Two frogs were placed in a carafe of water on the fire of a lit stove. At 20 deg. they appeared to be noticeably uncomfortable. Towards 30 degrees they screeched furiously beating the water out of the vase. They fell into terrible convulsions, ending in their death
with the whole body arched and tense, towards 35 deg. They were left in the heat up to 40°. Then one of them was taken out,
all tense and arched as has been said, and with the hardened muscles inflexible and stiff to the touch it remained for about a half hour before its preparation. As for the rest, it had not changed the
colour of its skin at all. Nonetheless, once skinned, its meat appeared quite reddish.
Having been prepared and tried in all fashions, it did not give any signs of its own electricity, neither was it affected by
artificial elec., not even with the relatively strong discharges from Leyden jars.
It was placed in water at room temperature
for well over one hour, but not at all did it gain flexibility in the joints, and little did it lose of the stiffness of the muscles.
Instead of disappearing, the reddish
colour grew in the bath. All attempts to make it show signs of its own electricity or to affect it with
artificial electricity were in vain.
It was replaced in the same bath. On pulling it out again at 7 in the evening, I found it was considerably softened and its muscles were flaccid. The leg, though, was stiff at the joint and neither heavy sparks nor discharges from a Leyden flask could manage to soften it or make the muscles tremble.
Finally, after 24 hours in the bath, the joints had slightly softened and the reddish colour had disappeared. Electric discharges had no effect.
The other frog was left in water heated to 60 °. The same straightening of the leg, tense arching of the trunk, inflexibility of the joints and rigidity of muscles. Two hours later the state was almost the same. The green colour of the skin near the stripped back had become whitish, the white of the stomach was slightly reddish, like meat and when stripped it seemed half cooked and almost disintegrated. Trying electricity was pointless.
A frog had died of natural causes in the container along with the others – probably dead a long time, since they had been enclosed for five days – and was then disembowelled (its innards were half black and were starting to putrefy) and prepared in the usual way. I was totally insensitive and not a single fibre gave the slightest sign of tremor at any test, not even when given heavy discharges from a Leyden Jar.
25 April
Two frogs were put into a flask of water, which was gradually heated on a stove. They began to thrash about violently at nearly 24°. At 32°and 33° one of them died and the other at 34°. So the flask was removed from the heat and the frogs removed.
They were somewhat stiff and bent. The forelegs particularly were rigid. When one was disembowelled, its innards were seen to be distinctly blackened. Its heart was still beating and, when pulled out and prodded, it continued to beat for a few minutes. Once I had finished preparing it, it still gave quite vigorous lasting signs of spontaneous electricity.
The other frog, meanwhile, came back to life, in other words it started moving again. So I threw it back into the flask of water, which had heated to 30°, and the frog again died. I left it in the water for about a quarter of an hour, before withdrawing it, when the water temperature had dropped to 26 ½ °. The frog was immediately prepared and its heart was found to be beating. Once removed, it continued beating for about a minute, pouring out a large amount of blood , after which it did not beat at all, even when pierced with a needle. Meanwhile the frog preparation was completed and its nerves were all armed with thin lead foil. It gave rather languid signs of spontaneous electricity, but only for a few minutes.
Three frogs were thrown into a flask of water, which was put to heat. The water took about 5 minutes to go from 15° to 35°. At about 25° they writhed remarkably, at 27° they thrashed about a lot and at 30° even more so. At 35°, when they all appeared dead, I removed the flask from the fire but I left the frogs in the water for another 25 minutes, which the water took to reduce its temperature to 30°. On taking them out, I found all three rigid, stone dead, with their hands clasped on their breasts, backs bent and taught, and the hind leg straight and inflexible. I put one on a table and left it there for an hour; another I wrapped in a cloth; the third I at once started to prepare.
I notice in this one that its heart was not beating and could not be excited. The muscles were white and as if separated from one another. The joints were quite rigid and inflexible apart from the toes.
Prepared as usual and the nerves completely armed, the frog gave no signs of animal electricity, nor did any of its muscles twitch when artificial electricity was discharged from a medium-sized flask at 30° on the Qu. el.
All liveliness showed itself therefore extinguished.
26 April
Three frogs, as above, were placed in water which went from 6° 31° in 6 minutes.
They thrashed about furiously as usual round 27°. When the vessel was removed from the heat at 31° they were still thrashing about but ceased after one minute and appeared dead, while the water dropped from 31 to 30.
Left thus in the bath for 12 minutes, during which time the temperature fell to 29°. One was then withdrawn and almost immediately recovered.
Another was removed after 14 further minutes, the bath temperature having fallen to 26 ½ °. This, having become extremely slight and flaccid, failed to recover movement nor breath nor any sign of life for a whole hour. After this time I tested it with artificial electricity and discovered it sensitive to a bare 5° Qu. El. with the simple conductor from one foot to the other.
Seeing this I moved on to preparing it and found its heart beating, though slowly and languidly. When I inserted the needle in the spinal cord, all the leg muscles convulsed as usual.
Preparation being completed, the frog gave such lively signs of spontaneous elec. as if it had suffered nothing in the hot bath and been prepared live.
The last one – the biggest of the three – I removed not from the bath for another 18 mins., the heat having dropped to 24°. It appeared extremely dead, just like the second but no as flaccid.
It was wrapped in cloth for 70 mins., after which nothing seemed changed. I opened the cloth. The heart beat not, nor did it react to a needle. Artif. elec. was tried but it needed a discharge of 6° Qu. El. to produce the slightest twitches; with 12° they were stronger; but to obtain jerking from the entire hanging trunk required a 25-30° discharge from the same flask.
Once completely prepared, it felt not a jot when the needle was inserted in the spinal cord, nor did it give any sign of spontaneous electricity. It was therefore dead to the 3rd degree, but as it reacted to artif. elec. of a certain strength one could not say dead to the 4th degree – or fully dead, which implies total disorganisation and which is soon followed by putrefaction.
Another frog was discovered dead inside the bell jar two days after it was put there with the others. It seemed recently dead. However, when opened up, its heart was not beating, nor did it respond to stimuli. Prepared and armed, it gave no sign of spontaneous elec. I reacted to artif. elec. but the flask required charging to approx. 3° Qu. El.
Puncturing and piercing its muscles with needles and large pins served nothing.
The following day, i.e. 18 [hours] later, still on the scaffold, it was again excitable by weak artif. elec.
A frog was prepared towards 7 in the evening for the exper. on spontaneous elec. It gave quite lively signs for half an hour and would have continued but gave up.
Towards midnight, having been exposed on the scaffold the entire time, it ceased giving signs but was sensitive to a greater charge of artif. elec. It twitched at the smallest degree therof, the positive being applied to the nerves. In the opposite direction it required a proportionally greater elec. charge, hence it seemed to be retaining some of its own spontaneous electricity.
Wrapped in a slightly damp cloth until midday the following day, I found the frog was somewhat able to be irritated by artif. elec. All that was required was a 12 [-inch] flask charged to about 5 ° on the Qu. El.
The writhing was notable and lasting, i.e. not only occurring at the moment of contact, and the leg muscles, and indeed the leg itself, became erect. For a few consecutive moments the biggest thigh muscles throbbed and trembled as if contorting. These spasms and tonic convulsions were gradually replaced, after some considerable time, by complete relaxation.
It is very worthy of note that this successive writhing and contorting of remarkable duration occurs only in already tired, withered and half dried-up muscles
(b). And this weakening happens not in the same or whole frog, or one recently prepared and in the same members, fresh and full of juice, and full of life. In this case, the writhing, jerking and leg-swinging is all much more vigorous but is only momentary, at the moment of discharge, both for spontaneous and artif. elec. Soon after, the contractions are replaced by
relaxation.
These convulsions and contortions happened in the same way and with the same electric force, whether discharging from one foot to the other or from the nerves to a foot, i.e. they needed a charge of 5 or 6 ° Qu. el. But having moistened the already dried-up nerves a little, 3° sufficed. And wetting them sufficiently, even only 5 on the Micro. el., applying the positive to the nerves; in the opposite direction, it needed more than double.
I returned to wrap it in the rather more dampened cloth and removed it about 4 p.m. I tried pricking the thigh muscles and driving needles in deeply, and indeed, using this method, there were signs of excitability still remaining, and – this was the astounding thing – better than in a frog prepared but two hours previously.
It was sensitive to the tests with artif. elec. as above, i.e. to the same degrees; but, whether because of laceration suffered by much puncturing or for some other reason, no longer did it exhibit continuous convulsions followed by writhing.
Put back into the slightly damp cloth, it was removed round midnight.. The artif. elec. had not entirely lost its ability to excite. Indeed all that was needed to produce convulsions was a 12in. flask charged to 4 or 5° on the Qu.
el.(1)
The frog removed first from the hot water at 31°, and which soon recovered life and movement, was kept enclosed (though not without air) in a wooden poor box for three days. For one whole day it appeared full of life. The second day it started to languish and continued fading until it was almost dead by 10o’clock on 29 Apr. It was finally found dead one hour after midday.
When subjected to the artif. elec. test, it convulsed as if alive or only recently killed.
Returned to the poor box, I removed it 8 hours later. It was thin thin, notably withered and very inflexible. It reacted, though, to electricity from the flask but needed a charge of about 4° Quad.El.
Rolled up in a slightly damp cloth. When I removed it at 9 the following morning, it was similarly rigid but not very. When tested, it showed no reaction, not even to a charge from the 12 [-inch] jar of 30° Qu. el.
Suspecting that this cam from the fact that it appeared too withered, I put it in a jar of water. But when I took it out at about 3.30p.m., it reacted not even to the 30°Qu.el. charge from the flask. It was therefore dead to the fourth degree. Indeed, when disembowelled, it was almost beginning to putrefy (the temperature was 19° and had been little less the previous day and night). Preparing it and arming its nerves served not at all, to obtain neither signs of spont. elect. nor convulsions with 30° Qu. el. from the flask.
29 April
At 11a.m. a small frog (one of those which had been kept for three days already in the tall bell jar open at the top, without food but a little grass which was thrown in on the second day but which they appeared not to have eaten) was decapitated and pierced the length of its spine with a long pin. This last wound, more than the first was as usual fatal, while the frog convulsed, stretched its legs and in but a few seconds lost all movement. Where only its head was docked, the frog maintained movement and life and jerked for more than a day.
When subjected shortly afterwards to the artif. elec. test, its legs and trunk convulsed as if it had been alive and whole, i.e. when given shocks from the flask of scarcely 2° on the Micr. el., tiny movements in the fingers and one or other muscles were observed. With 4°, 5°, 6° everything shook, with 8-10° it leapt and arched itself, etc.
It was wrapped in a cloth, which one could hardly call slightly humid, until 9 p.m., when the cloth appearing too dry was moistened a little.
At 9 the following morning (in all the meantime it had recovered no sign of movement or life) I tried with artif. elec. again. It gave the same signs. In other words the usual weak trembling in the legs and feet was excited by passing, from one to the other, a slight charge from the 12 [-inch] flask of 1° or slightly more on the Micr. el.
Shortly after that, with the frog remaining on the scaffold, much greater electric force was needed: 3 or 4 times more.
Prepared and armed as required for the spont. elec. test, it gave no signs. So it was pierced and transpierced by red-hot needles, without obtaining any result.
Pushing a pin into the armature, another into a leg, and thus transferring the discharge from the flask through the nerves to the leg, nought happened., it shook not, until about 3° on the Qu. el. This was probably because the nerves were so withered that they did not conduct the fluid well. When it was made to pass, at the moment of contact, from one leg to the other, even less sufficed. Half-an-hour’s moistening in the damp rag, and 2-3° on the Micr. el. sufficed. At 3.30 p.m., all the meantime wrapped in the damp cloth, art. el. was tried again. It was in such a bad state from all the puncturing that a charge of 30° on the Micr. El. was
needed.(2)
30 Apr. Temperature indoors: 17°
A lizard with half a tail, caught next day in the room, but sickly-looking, and more so when kept for 24 hours in a wooden poor box.(*)
Fastened to the scaffold by a big pin right through its head and another in one hind leg, it writhed a little under a discharge of scarcely 2° Micr. el. from the 12 [-inch] flask and jerked about when the charge was 10°. This was when directing the discharge from a front to a hind leg.
Once it was decapitated, it retained some leg movement for a few minutes, which was liveliest when pricked. When the tail was pricked, the whole body writhed; the same, but less so, pricking the back.
Then pushing a needle along the whole spinal cord, it gave extreme convulsions but not as violently as with a frog subjected to the same treatment. It appeared dead as far as the hind legs and the tail which was the only part that still wriggled a little when pricked with a needle.
After the few minutes this lasted, I inserted a long, thin needle up through the tail end of the body as far as half way to the waist, and then it was all finished and all limbs seemed dead. Subjected to the elec. test, a 2° Micr. el charge from the flask sufficed to arouse slight convulsions.
So I then wrapped the lizard in the slightly damp cloth at about 5 p.m. Round midnight, tested both whole and prepared, it writhed not at all under artif. elec., even with a flask charged to 20 Quad. El.
1 May
A drooping frog yet writhed slightly under a flask charged to ½° on the Micro. el C (2 on the very fine straw electrometer). After tormenting it thus for some time, it was put in a wooden poor box at about 2 p.m. At about 12, I found it absolutely dead with its back curved like a saddle. Attached to the scaffold, it needed a 16° charge on the same Micr. el. C, from the same flask, to writhe a little.
When prepared, it gave no sign of spont. elec., and with artif. elec. it only reacted at about 20° on the big straw Micr. el. Pricked and transfixed with needles, even red hot ones, it gave no reaction.
Indeed even a prepared frog, which gave most lively signs of spont. elec. at 3 p.m., put into a damp flask until about 12, I found it had lost not only most of its active vitality but also its passive, hardly twitching at a flask charge of 20° on the Qu. el.
Likewise, towards midnight on 2 May, another decapitated frog was finally killed by inserting a needle along its spinal cord, then enclosed in a wooden box, the following morning towards 9, gave no sign of any sort of irritability nor spontaneous electricity, and hardly any reaction to artif. elec., requiring from the 12 [-inch] flask a charge of 20° Qu. El. to twitch
slightly.(3)
The cylindrical Conductor, one in. wide and about 2 foot long, has a capacity about equal to the shield of an electrophorus 8 ins. in diameter. The Micr. El. C used here, which has thick short straws, shows 4° for each one of the Quad. el. B (whereas the micr. El. with long thin straws is 4 times as sensitive as that); therefore shows 16° for one on the Quad. El.
Therefore elec. from the Conductor, which goes to about 2 ½° on the Qu. el. scale (which, corrected, are really 4°), and to 15 or 16 on the Micr. El., suffice to cause slight convulsions in the frog hanging from the scaffold with one leg on one side and the other leg on the other side; and 2° on this Micro. El. make it jerk considerably.
Making the elec. pass from head to leg, or vice versa, it needs 6 or 7° on the Quad. El, i.e. 25-26 on the Micro. El. C. With only 20° on the Quad. El., the tremors are such that one hanging leg actually jerks.
Using the 12 [-inch] Leyden flask, the leg jerks with a charge of 1° on the Micro. El. (4 on the thin straw el.) and with ½° (2 on the most sensitive electrometers) it does not fail to contort most noticeably.
So that such a Conductor may give the slightest spark, scarcely visible in the dark, it must be charged to at least 5 or 6° on the Micro. el. C, i.e. 20-24° on the thin straw one. What’s more such a tiny little spark is not always visible.
3 May
A frog was prepared and suspended by the needle inserted in its spinal cord on one side and by one leg on the other. When a slight electric current was passed from the nerves to the muscles (viz. only 3° on the fine straw Micr. el.) from the simple Conductor: with
(4) deg. inversely…(5)
5 May- Temperature 11. Rainy weather.
Three frogs were put into a vessel of water on a stove. After 3 or 4 mins., the water having reached a temperature of 25°, the vessel was removed from the fire. The frogs appeared to be suffering but not greatly. After about a quarter of an hour, the water having cooled by 2°, it was reheated to 27° and again removed from the stove. The frogs stirred but without violence. After some minutes heating was recommenced up to 29 deg. The frogs appeared to suffer but continued living. Finally the heat was raised to 31°. The frogs then fell into agony and shortly after removing the vessel from the heat, the two smaller ones expired and then the third bigger, stronger one. The total time of continual reheating was 35 mins.
7 or 8 mins. after death I took one of the little frogs out to see if it would recover but it gave no sign of life for about three quarters of an hour.
I then subjected it to the artif. elec. test to see to what degree it might react and whether electrifying it, first weakly and then gradually more strongly, it might return to life. But no; it reacted not to the fairly strong discharges from a Leyden jar, neither when whole nor prepared. It gave even less sign of spontaneous electricity. When the needle was pushed into its spinal column, there was no convulsion, nor did the muscles give signs of irritability when pricked or transfixed. In short it was dead to the 4th degree.
The water was still tepid when I removed the other two frogs therefrom, an hour later. These were not quite as flaccid as the first but somewhat rigid at the joints in the strained right leg.
Testing one, I found it completely dead to the 4th degree, like the previous one.
The other I left entire and wrapped it in a cloth, where it remained for about an hour. Subjected to all the same tests as the other two, the result was the same, i.e. perfect insensibility and immobility, and
deathcomplete plenary
Three frogs were placed in a wide-mouthed vessel. A bunch of sulphur matches was burned, suspended from a cork stopper which did not entirely close the vessel. The frogs wriggled copiously and died one after the other at the end of several minutes.
The first was brought out almost dead, i.e. when its legs still moved a little, but it lost this even little movement in a few moments and, when subjected to tests, it almost entirely recovered its sensitivity under weak artif. elec. Then it was carefully prepared and gave signs of spontaneous electricity but weak and of short duration. Its flesh became visibly more rigid and crinkled, and after a few minutes, scarcely having finished giving signs of spont. elec., it ceased being responsive to artif elec, even discharges from the flask of about 20° Qu. El.
The other frogs were left in the sulphur fumes for several minutes, and I found them dead. I subjected one of them to the same tests as the first, with the same results, both regarding spont. and artif. elec. and the speed of withering of the flesh, which gave off a certain not entirely sulphurous odour.
N.B. On preparing these frogs, cutting off the backbone and inserting a needle into the medulla, the legs wriggled as usual, a sign of remaining sensitivity, but on pricking and perforating the muscles with big needles no contraction, no palpitation was observed.
Finally the third frog, tested about 3 hours after, reacted to no test and showed itself completely dead.
N.B. From all this it is evident that sulphur vapour, volatile sulphuric acid, penetrates into flesh and continues its mortifying action on nerves and muscles even after removing the frog from the fume-filled jar.
Revised and completed by John Coggan, Oxford University
