my great satisfaction, my expectations were completely fulfilled; I could here look down into the very bowels of the volcano, and truth and nature stood as it were unveiled before me." Thus situated in probable safety, the intrepid Spallanzani saw the following wonders.

The crater he found to be of a circular form, with edges composed of a chaos of sand, scoriæ, and lava; and he imagined the circumference to be about three hundred and forty feet. Similar to all other craters, that of Stromboli assumes the shape of a truncated inverted cone, the sides of which, from east to south, were gently inclined, but the remainder very steep. Many parts of this internal descent appeared to be incrusted with yellow substances, which he supposed to be the muriat of ammonia (sal ammoniac) or sulphur.

Fluid lava, resembling melted brass, red-hot, and liquid, filled the crater to a certain height, and this matter appeared to be influenced by two distinct impelling powers, the one whirling and agitated, and the other upwards; at times it rose rapidly, and when the surface had reached with in thirty feet of the edges of the crater, an explosion took place like a short clap of thunder, and at the same instant, a portion of the lava was hurled with inconceivable swiftness into the air, which was as instantaneously separated into numerous fragments, and those were accompanied by a copious discharge of sand, ashes, and smoke. Immediately before the eruption occurred, the lava appeared inflated, and large bubbles, some several feet in diameter, rose and burst, the detonation followed, and the lava sunk, till a repetition of this operation was commenced; during the rising, a sound issued from the crater like that produced by a liquid boiling violently in a cauldron. Many of the eruptions were

inconsiderable, that their effect could not be visible at a sinall distance from the mountain; in those the fragments constantly fell back into the gulph, with a sound, on their collision with the great mass of matter, similar to that produced by water when forcibly struck with flat staves; in the greater explosions, many of the pieces returned into the crater, some falling on the sides and rolling down, but many descended a precipice, formed by one side of the mountain, to the sea.

The pieces of scoriaceous lava, as they moved in the air, retained their red-hot appearance, though the sun shone clear; many of them came in contact during their progress, and, according to the degree of heat they possessed, they adhered, or were broken. The smoke seemed to be foreign to the lava, as none attended the fragments thrown into the air, and that which escaped passed through fissures, and at the moment the lava burst. According to Spallan zani's conjectures, the crater may be about twenty-five or thirty feet in depth, when the lava is raised to its greatest height, and upon its subsiding, forty or fifty. There are no visible marks of its ever having overflowed so as to descend like those of Ætna and Vesuvius.

"Though the ejections of the larger and heavier stones have short intermissions, those

of the lesser and lighter have scarcely any.

While this naturalist was employed in intense observation, the eruption suddenly ceased, the lava sunk to a greater depth than usual, and remained thus depressed; the fierce light subsided, and at the same instant, the various streams of smoke, issuing before silently from the apertures west of the crater, began to rush forth with a loud hissing noise, and the apertures to shine with a bright colour of fire. "I know nothing," says Spallanzani," to which the sound produced by the issuing of these fumes can be more proper ly compared than the blowing of large bellows into a furnace by which metals are melted; such as I have seen at Zalatna, in Transylvania, and Schemnitz and Kremnitz, in Hungary, except that those volcanic bellows roared a hundred times louder, and almost deafened the ear."

VOLCANO, one of the most considerable of the Lipari islands, in the Mediterranean, lying S. of the island of Lipari, from which it is separated by a deep channel, a mile and a half broad. It is 12 miles in circumference, and is a volcano, in the form of a broken cone, but now emits smoke only. Volcano, as well as all the rest of these islands, is supposed to have been originally the work of subterranean fire. Of the production of this island, in particular, Fazzello says that it happened in the early time of the Roman republic, and is recorded by Pliny and others.

VOLE. s. (vole, French.) A deal at cards, that draws the whole tricks (Swift). VO'LERY. s. (volerie, French.) A flight of birds.

Sometimes the word is used to signify a birdcage large enough for the birds to fly up and

down in it.

not the eye perceive how those showers of stones originate, it would be supposed that they fell from the sky the noise of the more violent eruptions, resembling that of thunder, and the darkness occasioned by the mounting cloud of smoke, precut the image of a tempest."

(Hale).

VOLKAMERIA, in botany, a genus of the class didynamia, order angiospermia. Calyx five-cleft; corol with all the divisions pointing one way; drupe two-seeded; nuts two-celled.

tivated.

1. V. aculeata. Prickly volkameria. 2. V. inermis. Ovate-leaved, smooth volkameria.

Both are shrubs, rising six or seven feet, with white flowers, void of odour.

VOLLEY. s. (volée, French.) 1. A flight of shot (Raleigh). 2. A burst; an emission of many at once (Shakspeare).

To Vo'LLEY. v. n. To throw out (Shak speare).

VOLLIED. a. (from volley.) Disploded; discharged with a volley (Philips).

VOLO, a town of European Turkey, in Janna, with a citadel and a fort. It was taken, and almost ruined, in 1655, by the Venetians. It is seated on a gulf of the same name, where there is a good harbour, 30 miles S.E. of Larissa. Lon. 22. 55 E. Lat. 39. 21 N.

VOLODIMIR, or VLADIMIR, a government of Russia, formerly a province of the government of Moscow. The soil is extremely fertile, and in the forests are innumerable swarms of bees.

VOLODIMIR, or VLADIMIR, a town of Russia, capital of a government of the same name. It is seated on the Kliasma, 110 miles E. by N. of Moscow. Lon. 40. 28 E. Lat.

55.53 N.

VOLOGDA, a government of Russia, divided into the two provinces of Vologda and Usting. It is a marshy country, full of forests, lakes, and rivers, and noted for its fine wool.

VOLOGDA, a town of Russia, capital of a province of the same name, and the see of an archbishop. It has a magnificent cathedral, several churches, a castle, and a fortress. The principal trade is in hemp, matting, leather, and tallow. It is seated in a marsh, on the river Vologda, which flows into the Sukhona, 257 miles N. by E. of Moscow. Lon. 39. 46 E. Lat. 59. 20 N.

VOLSCENS, a Latin chief, who discovered Nisus and Euryalus returning from the Rutulian camp loaded with spoils. He killed Euryalus, and was himself immediately stabbed by Nisus.

VOLSCI or VOLCI, a people of Latium, whose territories were bounded on the south by the Tyrrhene sea, north by the country of the Hernici and Marsi, west by the Latins and Rutulians, and east by Campania. Ancus king of Rome made war against them, and in the time of the republic they became formidable enemies, till they were at last conquered with the rest of the Latins.

VOLT. See VOLTE.

VOLTAIRE (Marie Francis Arouet de), a French writer of celebrity, born at Paris, 20th Feb. 1694. He was so feeble at his birth, that it was long doub ful whether he could be reared. From his earliest years he evinced superior powers, so that he said, he wrote verses before he left his cradle. He was educated in the college of Lewis the Great, where he made such progress, that Ninon de l'Enclos Left him 2000 livres to buy him a library. He

greater charms, and among the courtiers of Lewis XIV. he acquired those graces of deli cate humour and easy expression by which he was so much distinguished. His fondness for satire procured his imprisonment in the Bastille for one year, from which he was liberated by Orleans, who was pleased with the representation of Edipus, the first tragedy which he wrote, 1718. Some of his plays were afterwards unsuccessful, and the poet, indignant at the censures of his countrymen, left Paris, and came to England, where he was noticed by George 1. and queen Caroline, under whose patronage he published his Henriade. Flattered with this and with the handsome property which he had realized by the liberality of his subscribers, he in 1728 returned to Paris, and while he laboured by commerce to improve his income, he devoted the best part of his time to literary pursuits. His Bratus, the most nervous of his tragedies, appeared in 1730, and was soon succeeded by Zara, the most pathetic of his pieces. His lettres philosophiques at this time gave such offence for their indecent witticisms, that they were burnt by a decree of the parliament, and the author withdrew to the seat of madame de Chatelet. His Alzire, Mahomet, and Merope, produced soon after, placed him at the head of the dramatic poets of France, and introduced him to the court as the favourite of madame Pompadour. He was appointed gentleman of the bedchamber to the king, and historiographer of France, and in 1746 had a seat in the academy of sciences. Though thus popular, he yet found a host of rivals, and to fly from them, he retired to Berlin. The confidence of the Prussian monarch, and a liberal pension of 22,000 livres, for a while commanded his attachment, but a quarrel with Maupertuis, who was at the head of the Berlin academy, and that spirit of independence which always marked his conduct, soon after brought on his disgrace, and after being dispossessed of a volume of royal verses, which he wished to carry away, he left the kingdom. The publication of an obscene poem at that time rendered his return to Paris dangerous, and therefore after staying one year at Colwar, he purchased an estate near Geneva, where he fixed his residence. This place he soon abandoned for Ferney, on the borders of France, where he established a colony of industrious artisans, and received in progress of time the homage and the respect of the learned of Europe. He received the adulation of the great, and the liberal presents of crowned heads, especially of the king of Prussia, and of the empress Catherine, and continued long to direct the taste and the literature of the world. At last, in 1778, he ventured to exchange the tranquillity of Ferney for the capital, and surrounded with glory and with wealth, he ap peared at Paris, where he was received with unusual honours by all the learned bodies, and crowned with the poetic wreath in the theatre, amidst applauding thousands. These honours, and the complimentary visits of ceremony

which they produced, were, however, too burdensome for his great age and change of regimen, and continued fatigue inflamed his blood and brought on a hæmorrhage. As if foreboding his end, he declared when he reached Paris, that he came to seek glory and death, and when presented by an artist with a picture of his triumph, he observed, "a tomb would be fitter for me than a triumph." When unable to enjoy his usual rest, and unable to bear his reflections, he took a large dose of opium, which deprived him of his senses, and he died soon after, 30th May, 1778. He was buried at Sellieres, between Nogent and Troyes, and his remains were, during the revolution, removed to the church of St. Genevieve, at Paris, by a decree of the convention. Voltaire, as the leader of a new sect, has caused a revolution in wit and inorals, and whilst he has often exerted his powerful talents to promote the cause of reason and of humanity, to inspire princes with toleration, and with a horror for war, he has too often-exerted himself in extend

ing principles of irreligion, anarchy, and libertinism. Ever inconstant, he was the free thinker at London, the Cartesian at Versailles, the pretended Christian at Nancy, and the undisguised infidel at Berlin. From the high character of the moralist, he frequently descended into the buffoon, from the philosopher he became an enthusiast, from mildness he passed to passion, from flattery to satire, from the love of money to the love of luxury, from the modesty of a wise man to the vanity of an impious wit. It has been said, that his phy siognomy partook of that of the eagle and of the ape, and his character exhibited him occasionally with sensibility, but void of affection, voluptuous, but without passions, open without sincerity, and liberal without generosity. As a man of letters he must stand on very high ground for versality of talent, for brilliancy of imagination, for astonishing ease, for exquisite Laste, and for vast extent of knowledge. He wrote, besides, several tragedies, the last of which was Irene-several comedies, the best of which are, l'indiscret, l'enfant prodigue, and Nanine-operas-fugitive pieces essai sur l'histoire generale-les siecles de Louis XIV. and Louis XV.-history of Charles XII.-of the czar Peter-melanges de literature-dictionaire philosophique-philosophie de l'his toire, and other works of impious tendencytheatre of Peter and Th. Corneille, &c. The most correct edition of his works is that of Geneva, in 30 vols. 4to. and the most copious, that of Basil, in 71 vols. 8vo.

Condorcet records of Voltaire, First, that he conceived the design of overturning the Christian religion, and that by his own hand. "I am wearied," said he, of hearing it repeated that twelve men were sufficient to es tablish Christianity; and I wish to prove that there needs but one to destroy it." Secondly, that in pursuit of this object, he was threatened with a prosecution; to avoid which he received the sacrament, and publicly declared his respect for the church, and his disdain for those who had called in question his Christi

anity! Thirdly, that in his last illness, in Paris, being desirous of obtaining what is called Christian burial, he sent for a priest, to whom he declared that he died in the catholic faith in which he was born." Fourthly, that another priest (curate of the parish) troubled him with questions. Among other things he asked, "Do you believe the divinity of Jesus Christ?" "In the name of God, sir," replied Voltaire, "speak to me no more of that man, but let me die in peace." How different from the language of David, Psalm xvii. 15.

For an account of Voltaire's shameful interpolations, &c. in his edition of Pascal's Thoughts, see PASCAL.

VOLTAISM, that curious and important branch of electricity, which depends upon metallic combinations. For the earliest insulated facts which paved the way to this science, we are indebted to professor Galvani; for their expla nation and application to purposes of real utility, we are indebted to professor Volta; and for the

grand and simple law of nature by which they operate in the production of effects, we are indebted to sir Humphrey Davy.

logna discovered accidentally, that the crural About the year 1790, professor Galvani of Bonerve of a frog cut up for soup for his wife's dinner, contracted and became convulsed upon the application of a knife wetted with water; as the story is told by other writers, he perceived whilst he was one day dissecting a frog in a room where some of his friends were amusing themselves with electrical experiments, that the body of the animal was shaken with a violent convulsion, in consequence of a spark being drawn from the conductor of the machine at the time he was touching one of its nerves. Astonished at might be owing to his having wounded the nerve, the phenomenon, and at first imagining that it he pricked it with the point of his knife, to assure himself whether or not this was the case, but no motion of the frog's body was produced. He now touched the nerve with the instrument as at first, and directed a spark to be taken at the same time from the machine, on which the contractions were renewed. Upon a third trial, the animal remained motionless; but observing that he held his knife by the handle, which was made of ivory, he changed it for a metallic one, and immediately the movements took place, which never was the case when he used an electric substance.

After having made a great many similar experiments with the electrical machine, he resolved to prosecute the subject with atmospherie electricity. With this view he raised a conductor on the roof of his house, from which he brought an iron wire into his room. To this he attached metal conductors, connected with the nerves of the animals destined to be the subjects of his experiments; and to their legs he fastened wires which reached the floor. These experiments were not confined to frogs alone. Different animals, both of cold and warm blood, siderable movements were excited whenever it were subjected to them; and in all of them conlightened. These preceded thunder, and corresponded with its intensity and repetition; and even when no lightning appeared, the movements took place when any stormy cloud passed over the apparatus. That all these appearances were produced by the electric fluid was obvious.

Having soon after this suspended some frogs from the iron palisades which surrounded his garden, by means of metallic hooks fixed in the spines of their backs, he observed that their muscles contracted frequently and involuntarily, as if from a shock of electricity. Not doubting that the contractions depended on the electric fluid, he at first suspected that they were connected with changes in the state of the atmosphere. He soon found, however, that this was not the case; and having varied, in many different ways, the circumstances in which the frogs were placed, he at length discovered that he could produce the movements at pleasure by touching the animals with two different metals, which, at the same time, touched one another either immediately or by the intervention of some other substance capable of conducting electricity.

All the experiments that have yet been made may be reduced to the following, which will give the otherwise uninformed reader a precise notion of the subject.

Lay bare about an inch of a great nerve, leading to any limb or muscle. Let that end of the bared part which is farthest from the limb be in close contact with a bit of zinc. Touch the zinc with a bit of silver, while another part of the silver touches, either the naked nerve, if not dry, or, whether it be dry or not, the limb or muscle to which it leads. Violent contractions are produced in the limb or muscle, but not in any muscle on the other side of the zinc.

Or, touch the bared nerve with a piece of zinc, and touch, with a piece of silver, either the bared nerve, or the limb; no convulsion is observed, till the zinc and silver are also made to touch each other.

A fact so new, illustrated by many experiments and nuch ingenious reasoning, which professor Galvani soon published, could not fail to attract the attention of physiologists all over Europe; and the result of a vast number of experiments, equally cruel and surprising, has been from time to time laid before the public by Valli, Fowler, Mon ro, Volta, Humbolt, and others.

Frogs, unhappily for themselves, have been found the most convenient subjects for these experiments, as they retain their muscular irritability and susceptibility of the galvanic influence very long. Many hours after they have been decapitated, or have had their brain and spinal marrow destroyed, strong convulsions can be produced in them by the application of the metals. A le; separated from the body will often continue capable of excitement for several days. Nay, very distinct movements have been produced in frogs pretty far advanced in the process of putrefaction. Different kinds of fishes, and many other animals, both of cold and warm blood, have beer subjected to similar experiments, and have exhibited the same phenomena; but the warm blooded animals lose their susceptibility of galvan ism, as of every other stimulus, very soon after death.

Almost any two metals will produce the movements; but, it is believed, the most powerful are the following, in the order in which they are here placed: 1. Zine; 2. Tin ; 3. Lead; in conjunction with, 1. Gold; 2. Silver ; 3. Molybdena; 4. Steel; 5. Copper. Úpon this point, however, authors are not perfectly agreed.

The process by which these singular phenomena are produced consists in effecting, by the use of the exciting apparatus, a mutual com

munication between any two points of contact, more or less distant from one another, in a system of nervous and muscular organs. The sphere of this mutual communication may be regarded as a complete circle, divided into two parts. That part of it which consists of the organs of the animal under the experiment has been called the animal are; that which is formed by the galvanic instruments has been called the excitatory arc. The latter usually consists of more pieces than one; of which some are named stays, braces, &e. others communicators, from their respective uses.

Besides the effects thus produced on the muscles, the impressions made on the organs of sense are equally remarkable. And as the experiments illustrating them may be easily repeated, we shall specify some of the most interesting. For instance, if a thin plate of zinc be placed on the upper surface of the tongue, and a half-crown, shilling, or silver tea-spoon, be laid on the lower surface of the tongue, and both metals after a short space of time be brought into contact, a peculiar sensation, similar to taste, will be perceived at the moment when the mutual touch happens. If the silver be put beneath, and the zinc upon the tongue, the same sensation will arise, but in a weaker degree, resembling diluted ammoniac, from which it in all probability derives its origin.

If a silver probe be introduced as far as con. venient into one of the nostrils, and then be brought into contact with a piece of zinc placed on the tongue, a sensation not unlike a strong flash of light will be produced in the corresponding eye, at the instant of contact. A similar perception will result, both at the moment of con tact and at that of separation, if one of the metals be applied as high as possible between the gums and upper lip, and the other in a similar situation with the under lip, or even under the tongue. Lastly, when a probe or rod of zine, and another of silver, are introduced as far back as possible into the roof of the mouth, the irritations produced by bringing the external ends into contact, are very powerful; and that caused by the zinc is similar in taste to the sensation arising from its application to the tongue.

No method has hitherto been discovered of applying the Galvanic influence in such a manner as to affect the senses of smell, hearing, and touch; though several eminent philosophers have carefully investigated the subject. Nor are the causes of these phenomena clearly ascertained; Galvani and many of his followers supposing them to depend on the electric fluid, while others attribute them to the influence of various physical agents.

Mr. Creve, surgeon in Wurtzburg, had an opportunity of observing the irritation on the leg of a boy, which had been amputated far above the knee in the hospital of that city. Immediately after the amputation, Mr. Creve laid bare the crural nerve (kiekehlnerven), and surrounded it with a slip of tinfoil. He touched at once the tinfoil and the nerve with a French erownpiece. In that instant the most violent convulsions took place in the leg both above and below the knee. The remainder of the thighbone bent with fores toward the calf; the fool was more bent than extended. All these motions were made with much force and rapidity. None were produced when the tinfoil was taken away, or when a steel pincer was used in place of a piece of silver, or when the tin or silver was covered with blood: but they

were renewed when these obstacles were removed. These phenomena continued till 38 minutes after the amputation, when the limb became cold.

Dr. Christopher Heinrich Pfaff (in Dissertatione de Electricitate Animali, Stutgardt, 1793: see also Gren's Journal der Physk, T. viii. p. 196, &c.) has classed the phenomena of muscular contraction in a very orderly and perspi

cuous manner.

The general form of his experiments is the same with that which we have already described; but the following varieties were observed:

The nerve being coated with tinfoil, it was always observed that the contractions were stronger when the silver first touched the muscle, and then the coating. If it touched the coating first the effects were always, and very sensibly, weaker.

They were still stronger when the silver did not touch the muscle at all, but only the nerve and its coating.

When the contractions were weaker at the beginning, they also ceased sooner.

No contraction ensued from touching the coating only, or the nerve only, or the muscle only, with the silver.

Continuing the contact did not occasion any repetition of the contractions, except in some cases, where the silver was drawn along different parts of the coating, while its other end remained in contact with the nerve.

The contractions took place only in the muscles to which the nerve led.

Their strength and duration were greater when the surfaces of contact were greater, and when the two metals touched each other in points or sharp edges.

A ligature, with a silk thread below the coating (that is, between the coating and the muscle, or part of the nerve touched by the silver), prevented all contraction; but not if the ligature was between the coating and the brain. If the nerve was cut through below the coating, and the parts separated a quarter of an inch, no contraction followed by touching the coating and the nerve or muscle: but it took place, if the parts were brought into contact; or even if a piece of any other nerve was put between the parts.

If a considerable part of a bared nerve was in sulated and coated, partly with tinfoil and partly with silver, contractions were produced in the muscle to which it led whenever the two metals were brought into contact.

If one crural nerve be coated with tin, and the other with silver, contractions are produced in both legs by bringing the metals into contact.

If the nerve be dry under the coating, or when the silver touches it, or in both places, we have no contractions; but they begin as soon as we moisten the nerve.

Dr. Pfaff infers from these phenomena, that the nerve alone is subject to the irritation produced by the two metals.

If the prepared frog be immersed in water, so that the coating touches the water, contractions are produced by touching the coating above water with the silver, while another part of the silver touches the nerve, or the muscle, or even dips pretty deep in the water.

No such thing happens in oil; or at best, the contractions are very slight.

Pfaff could not produce contractions without employing two metals, or a metal and charcoal.

VOL. XI-PART II.

A very thin covering of muscular flesh on the nerve did not altogether prevent the contrac tions, and in many cases did not sensibly dis minish them.

If a piece of silver be laid on the muscles of the breast or belly, and be brought into contact with the tin coating on the lumbal region, only the muscles of the breast or belly are affected, but not those of the legs.

Pfaff observes, that the involuntary muscles are not affected by galvanism; and refers for convincing proofs to a dissertation by Dr. Ludwig, shewing that the heart is not furnished with nerves. (Scriptor. neurolog. minor. select. vol. ii.)

Professor Aldani, the nephew of Galvani, has pursued the interesting subject with great zeal and success. Early in the year 1803 the professor was in England, and exhibited several very curious galvanic experiments. Among other im portant facts, it was decisively shewn,

1. That a vital attraction subsists between a nerve and muscle: for the suspended sciatic nerves of a frog, after detaching the spine, being brought near the intercostal muscles of a dog, while the assistant who held the frog did, with his other hand, touch the muscles of the thigh of the dog (thus forming a circle); in this situation, the nerves suspended approached, and came into contact with the muscle, as evidently as a silken thread is attracted by sealing-way.

2. The heart of a rabbit was excited to action in a little time after the animal was killed; but vitality disappeared much sooner than in the other muscles: so that this organ is the primum, and not, as Harvey asserted, the ultimum moriens. The lungs, liver, and spleen could not be excited to action, even immediately after the animal was killed.

3. The most important fact of all was that of exciting contractions by making a circle of nerves and muscles of different animals, without any metallic exciter or conductors.

4. The head of an ox, recently decapitated, ex. hibited astonishing effects: for, the tongue being drawn out by a hook fixed into it, on applying the exciters, in spite of the strength of the assistant, the tongue was retracted, so as to detach itself by tearing itself from the hook at the same time a loud noise issued from the mouth by the absorption of air, attended by violent contortions of the whole head and eyes.

Aldani also availed himself of the opportunity afforded by the execution of Forster on the 17th of January, for the murder of his wife and child, to repeat his galvanic experiments. A liberal grant had been made him of the use of that subject, by Mr. Keate, surgeon to the king, and master of the college of surgeons, who was himself present on this occasion. The result of this experiment promises great advantages to the interests of humanity, especially in cases of apparent death by drowning, and other cases of asphyxia. These gentlemen, we understand, found that the corpse, by means of galvanism, was made to exhibit very powerful muscular contrac tions before dissection, and that afterwards these contractions continued for seven hours and a half, On the first application of the process to the face, the jaw of the deceased criminal began to quiver, and the adjoining muscles were horribly contorted, and one eye was actually opened. In the subsequent part of the process, the right hand was raised and clenched, and the legs and thighs were

N