was used, and different internal means were employed without any benefit. The patient returned home.

In February, 1809, she was affected with general weakness; and soon afterwards a difficulty and finally incapacity in walking. She remained in this state for several months.

At the beginning of August she was carried to the HotelDieu, they gave her two purges and applied a blister to the nape of the neck; these means, however, were not successful.

By the 5th of September the pains in the head had almost ceased: The face was bloated, there was stupor, continual debility in the superior and lower extremities; the pupils were much dilated, and the blindness appeared irremediable.

On the 10th, there was cophosis on the left side, and occasionally, difficulty of hearing on the right side. Her voice was altered, the tongue was inclined towards the left side. The faculties of the mind were little interrupted, except the memory, which was treacherous. She had a cough without expectoration; she could lie easy on either side, but her power of motion was very limited both from paralysis, and on account of her great weakness.

15th of September. Sleep lasted longer than in the natural state. The pulse was small, weak, and rather frequent.

25 and 26. She could hardly open her mouth; somnolency and coma succeeded, involuntary dejection, and labo rious breathing, and on the following day she died. Catamenia ceased only in September.

Dissection.-The state of the brain: The lateral ventricles contained 2 oz. of serosity; the pituitary gland was twice as large as usual, and contained several puriform spots with a foetid smell; it adhered strongly to the posterior clinoid processes, these, but chiefly the left, were nearly destroyed, the sella turcica and its membranous covering were in a similar condition. The sphenoidal membranes were filled with serosity mixed with pus.

In the left lateral and middle cavity of the cranium, was a tumour which had originated in the bottom of the meatus auditorius internus, and occupied three fourths of the posterior surface of the petrous portion of the temporal bone. The orifice of this meatus was destroyed, and in its place was a cavity which was filled by the tumour. The tumour was of fourteen lines in diameter, and 34 drams in weight, its structure partly fibrous, and partly carcinomatous. A very thin layer of dura mater covered it, it reached to the tentorium, and pressed against the annular protuberance, which it pushed about three lines out of its situation to the right..

Reflections.

Reflections.-May not the cause of the blindness, of the deafness, and of the other phænomena, be thus explained?

1st. The blindness from caries of the sphenoidal bone, and the communication of the sphenoidal membranes with the brain. The external air would have penetrated into the cranium if it had not been hindered by the pituitary gland, which it caused to inflame; and this gland mechanically closed the opening which the caries had made; and as it exceeded its usual rise and projected as far as the optic foramen, it must have made pressure upon the optic nerves, and from this pressure resulted the paralysis of the retina, and loss of sight.

2d. As to the loss of hearing, the tumour which occupied a portion of the meatus auditorius internus, had not destroyed the auditory and facial nerves, but only compressed them. The pressure must chiefly have acted on the first, and bence resulted the deafness on that side.

3d. We may explain the universal paralysis from the pressure on the annular protuberance by the aforesaid tumour; a pressure which more or less interrupted the influence of the brain upon the spinal marrow.

Observations on Luminous Animals. By J. MACART NEY, Esq.

(Concluded from page 424.)

THE phenomenon of animal light has been attempted to be

explained in different ways. By many persons it was formerly ascribed to a putrefactive process, but since the modern theories of combustion became known, it has been generally believed to depend upon an actual inflammation of the luminous substance, similar to the slow combustion of phosphorus. Others have accounted for the luminous effect, by sup posing the matter of light to be accumulated, and rendered latent under particular circumstances, and afterwards evolved in a sensible form.

The opinion of the light of living animals being the consequence of putrefaction, is evidently absurd, and contradictory to all observation on the subject. It has been proved by the experiments of Dr. Hulme and others, that even the luminous appearances of dead animals are exhibited only during the first stages of the dissolution of the body, and that no light is emitted after putrefaction has really commenced.

Spallanzani, who was the most strenuous advocate for the phosphorescent

phosphorescent nature of animal light, stated that glowworms shone more brilliantly when put into oxygen gas; that their light gradually disappeared in hydrogen or in azotic gas, and was instantly extinguished in fixed air; that it was also lost by cold, and revived by the application of a warm temperature. He conjectured that the luminous matter of these insects was composed of hydrogen and carbonated hydrogen gas.

Forster relates, in the Lichtenberg Magazine for 1783, that on putting a lampyris splendidula into oxygen gas, it gave as much light as four of the same species in common air.

Carradori has made some experiments upon the lucciole, (lampyris italica) which led him to deny its phosphores cence. He found that the luminous portion of the belly of the insect shone in vacuum, in oil, in water, and different liquids, and under different circumstances, where it was excluded from all the communication with oxygen gas. He accounts for the result of Forster's experiment, by supposing, that the worm shone more vividly, because it was more animated in oxygen gas than in common air.

Carradori adopts on this subject the doctrine of Brugnatelli, and ascribes the luminous appearances of animals, to the condensation and extrication of light in particular organs, which had previously existed in combination with the substance of their bodies. He supposes the light to be originally derived from the food, or the atmospheric air taken into the body; in short, that certain animals have the peculiar property of gradually imbibing light from foreign bodies, and of afterwards secreting it in a sensible form.*

The following experiments which I made upon this subject, would lead me to make different conclusions than those of the preceding authors.

Experiment 1.-A glow worm was put into a glass of water, in which it lived nearly two hours, and continued to emit light as usual, until it died, when the luminous appearance entirely ceased.

Experiment 2.-The luminous substance was extracted from the beforementioned glow-worm, and from others killed in different ways, but it afforded no light.

Experiment 3.-The sacs containing the luminous matter were cut from the bellies of living glow-worms, and shone uninterruptedly for several hours in the atmosphere, and after their light became extinct, it was revived by being moistened

* Annal di Chimica, Tomo xiii. 1797.

with

with water; some of these were put into water in the first instance, in which they continued to shine unremittingly for

48 hours.

Experiment 4 -The luminous substance of a glow-worm was exposed to a degree of heat which would have been sufficient to inflame phosphorus, without increasing the bril liancy of its light; and farther, it could not be made to bura by being applied to a red hot iron, or to the flame of a candle.

Experiment 5.-A delicate thermometer was introduced amongst some living glow-worms, during the time they gave out much light the temperature of the room being 69, the instrument rose to 75, 76, and 77, according to circumstances, as the warmth was reflected from the hand, or dissipated by the worm crawling over cold substances. The lu minous portion of the tail, when very brilliant, appeared to raise the thermometer more quickly than the other parts of the body, but it was not invariably the case. When shining strongly, I thought that the luminous rings communicated the sensation of warmth to the hand, but this was probably a deception, as the actual degree of heat was not sufficient for such an effect. It should however be mentioned, that in Templar's observations on the glow-worm, he said his feelings deceived him, if he did not experience come heat from the shining of the insect.*

Experiment 6.-To satisfy myself how far the evolution of heat during the shining of glow-worms, depended upon the life of the animals, I cut off the luminous portion of the tail from several living worms, and I found that if the thermometer was applied to them immediately, it was raised by them one or two degrees; but after these parts were dead; although they continued to emit light, they produced no effect whatever upon the instrument.

Experiment 7.-Some hemispherical medusa were put into a spoon, containing a small quantity of sea water, and held over a burning candle. As soon as the water became heated the medusæ appeared like illuminated wheels, the spots at the margin and center alone emitting light; in which manner they shone vividly and permanently for about 20 seconds, when they shrunk and died, after which they were no longer luminous.

Experiment 8.-Some of the same species were put into spirits a strong unremitting light was instantly given out, which issued from the central and marginal parts, as in the preceding experiment, and continued until they died.

*Phil. Trans. No. 75.

Experiment

Experiment 9.-Some of the scintillating and hemispherical species of medusa, contained in a small glass jar, were introduced into the receiver of an air pump, and the air being exhausted, they shone as usual when shaken; if any difference could be perceived, the light was more easily excited, and continued longer in vacuum.

I wished next to try the influence of electricity on the luminous property of animals.

Experiment 10.-A medusa hemispherica was placed in a small glass dish, containing a quantity of water, merely sufficient to allow the animal to preserve its figure; being insulated, it was electrified, and sparks drawn from it, which had not the slightest effect; the experiment was repeated several times with different individuals, but without exciting the animals to throw out light.

Experiment 11.-Some hemispherical medusæ were placed in contact with the two ends of an interrupted chain, and slight electric shocks passed through them. During the very moment of their receiving the shock no light was visible, but immediately afterwards the medusa shone like illuminated wheels, which appearance remained for some seconds. Upon the closest inspection with a magnifying glass, no contractile motion could be perceived to accompany the exhibition of the light. The application of electricity in this instance seems to have acted merely as a strong mechanic shock.

The above experiments on the luminous medusa were made at Herne, with the assistance of George May, Esq. of Stroud-house, and in the presence of a large company, capable of accurately distinguishing their results.

It seems proved by the foregoing experiments, that so far from the luminous substance being of a phosphorescent nature, it sometimes shews the strongest and most constant light, when excluded from oxygene gas; that it in no circumstances undergoes any process like combustion, but is actually incapable of being inflamed; that the increase of heat, during the shining of glow-worms, is an accompaniment, and not an effect of the phenomenon, and depends upon the excited state of the insect; and lastly, that heat and electricity increase the exhibition of light, merely by operating like other stimuli upon the vital properties of the animal.

In confirmation of these opinions, I may quote the high authority of the Secretary of this Society, who has found that the light of the glow-worm is not rendered more brilliant in oxygene, or in oxygenated muriatic gas, than in common air; and that it is not sensibly diminished in hydrogene gas. I may further add, that Spallanzani's experiments of dif fusing the luminous liquor of the medusa in water, milk (No. 148.)

3 U

and