'A day with not too bright a beam;A warm, but not a scorching sun.'"
'A day with not too bright a beam;A warm, but not a scorching sun.'"
'A day with not too bright a beam;A warm, but not a scorching sun.'"
'A day with not too bright a beam;
A warm, but not a scorching sun.'"
A very amusing and philosophical conversation on those natural phenomena, which have been vulgarly viewed as prophetic of dry or wet weather, may be well adduced as illustrative of that genius which, by the aid of a light of its own, imparts to the most trite objects all the charms of novelty.
"Poietes.—I hope we shall have another good day to-morrow, for the clouds are red in the west.
"Physicus.—I have no doubt of it, for the red has a tint of purple.
"Halieus.—Do you know why this tint portends fine weather?
"Physicus.—The air when dry, I believe, refracts more red, or heat-making rays; and as dry air is not perfectly transparent, they are again reflected in the horizon. I have generally observed a coppery or yellow sunset to foretell rain; but, as an indication of wet weather approaching, nothing is more certain than a halo round the moon, which is produced by the precipitated water; and the larger the circle, the nearer the clouds, and consequently the more ready to fall.
"Halieus.—I have often observed, that the old proverb is correct—
'A rainbow in the morning is the shepherd's warning;A rainbow at night is the shepherd's delight.'
'A rainbow in the morning is the shepherd's warning;A rainbow at night is the shepherd's delight.'
'A rainbow in the morning is the shepherd's warning;A rainbow at night is the shepherd's delight.'
'A rainbow in the morning is the shepherd's warning;
A rainbow at night is the shepherd's delight.'
—Can you explain this omen?
"Physicus.—A rainbow can only occur when the clouds containing or depositing the rain are opposite to the sun; and in the evening the rainbow is in the east, and in the morning in the west; and as our heavy rains in this climate are usually brought by the westerly wind, a rainbow in the west indicates that the bad weather is on the road, by the wind, to us; whereas the rainbow in the east proves, that the rain in these clouds is passing from us.
"Poietes.—I have often observed, that when the swallows fly high, fine weather is to be expected or continued; but when they fly low and close to the ground, rain is almost surely approaching. Can you account for this?
"Halieus.—Swallows follow the flies and gnats, and flies and gnats usually delight in warm strata ofair; and as warm air is lighter, and usually moister than cold air, when the warm strata of air are high, there is less chance of moisture being thrown down from them by the mixture with cold air; but when the warm and moist air is close to the surface, it is almost certain, that as the cold air flows down into it, a deposition of water will take place.
"Poietes.—I have often seen sea-gulls assemble on the land, and have almost always observed, that very stormy and rainy weather was approaching. I conclude that these animals, sensible of a current of air approaching from the ocean, retire to the land to shelter themselves from the storm.
"Ornither.—No such thing. The storm is their element; and the little petrel enjoys the heaviest gale; because, living on the smaller sea insects, he is sure to find his food in the spray of a heavy wave. And you may see him flitting above the edge of the highest surge. I believe that the reason of the migration of sea-gulls and other sea birds to the land, is their security of finding food. They may be observed, at this time, feeding greedily on the earth worms and larvæ driven out of the ground by severe floods; and the fish on which they prey in fine weather in the sea, leave the surface when storms prevail, and go deeper. The search after food, as we agreed on a former occasion, is the principal cause why animals change their places. The different tribes of the wading birds always migrate when rain is about to take place; and I remember once in Italy having been long waiting, in the end of March, for the arrival of the double snipe in theCampagna of Rome: a great flight appeared on the 3rd of April, and the day after heavy rain set in, which greatly interfered with my sport. The vulture, upon the same principle, follows armies; and I have no doubt, that the augury of the ancients was a good deal founded upon the observation of the instincts of birds. There are many superstitions of the vulgar owing to the same source. For anglers, in spring, it is always unlucky to seesinglemagpies; buttwomay be always regarded as a favourable omen; and the reason is, that in cold and stormy weather, one magpie alone leaves the nest in search of food, the other remaining sitting upon the eggs or the young ones; but when two go out together, the weather is warm and mild, and thus favourable for fishing.
"Poietes.—The singular connexions of cause and effect, to which you have just referred, make superstition less to be wondered at, particularly amongst the vulgar; and when two facts, naturally unconnected, have been accidentally coincident, it is not singular that this coincidence should have been observed and registered, and that omens of the most absurd kind should be trusted in. In the West of England, half a century ago, a particular hollow noise on the sea-coast was referred to a spirit or goblin, called Bucca, and was supposed to foretell a shipwreck; the philosopher knows, that sound travels much faster than currents in the air—and the sound always foretold the approach of a very heavy storm, which seldom takes place on that wild and rocky coast, surrounded as it is by the Atlantic,without a shipwreck on some part of its extensive shores.[112]
"Physicus.—All the instances of omens you have mentioned are founded on reason; but how can you explain such absurdities as Friday being an unlucky day, the terror of spilling salt, or meeting an old woman? I knew a man of very high dignity, who was exceedingly moved by these omens, and who never went out shooting without a bittern's claw fastened to his button-hole by a riband—which he thought ensured him good luck.
"Poietes.—These, as well as the omens of deathwatches, dreams, &c. are for the most part founded upon some accidental coincidences; but spilling of salt, on an uncommon occasion, may, as I have known it, arise from a disposition to apoplexy, shown by an incipient numbness in the hand, and may be a fatal symptom; and persons dispirited by bad omens sometimes prepare the way for evil fortune; for confidence in success is a great means of insuring it. The dream of Brutus, before the field of Philippi, probably produced a species of irresolution and despondency, which was the principal cause of his losing the battle; and I have heard, that the illustrious sportsman, to whom youreferred just now, was always observed to shoot ill, because he shot carelessly, after one of his dispiriting omens.
"Halieus.—I have in life met with a few things which I found it impossible to explain, either by chance, coincidences, or by natural connexions; and I have known minds of a very superior class affected by them,—persons in the habit of reasoning deeply and profoundly.
"Physicus.—In my opinion, profound minds are the most likely to think lightly of the resources of human reason; it is the pert, superficial thinker who is generally strongest in every kind of unbelief. The deep philosopher sees chains of causes and effects so wonderfully and strangely linked together, that he is usually the last person to decide upon the impossibility of any two series of events being independent of each other; and in science, so many natural miracles, as it were, have been brought to light,—such as the fall of stones from meteors in the atmosphere, the disarming a thunder-cloud by a metallic point, the production of fire from ice by a metal white as silver, and referring certain laws of motion of the sea to the moon,—that the physical enquirer is seldom disposed to assert, confidently, on any abstruse subjects belonging to the order of natural things, and still less so on those relating to the more mysterious relations of moral events and intellectual natures."
Old Isaac Walton has amused us with a variety of absurd fables and superstitions: the author of Salmonia, on the other hand, touches, as with the spear of Ithuriel, the monsters and prodigies of theolder writers, and they at once assume the forms of well-ascertained animals, or vegetables. Thesea snakeseen by American and Norwegian captains, appears as a company of porpoises, which in their gambols, by rising and sinking in lines, would give somewhat the appearance of the coils of a snake. TheKraken, or island fish, is reduced into an assemblage ofurticæ marinæ, or sea blubbers. TheMermaid, into the long-haired seal;[113]and lastly, the celebrated Caithness Mermaid assumes the unpoetical form of a stout young traveller;—but this story is far too amusing to be dismissed with a passing notice.
"A worthy Baronet, remarkable for his benevolent views and active spirit, has propagated a story of this kind, and he seems to claim for his native country the honour of possessing this extraordinary animal; but the mermaid of Caithness was certainly agentleman, who happened to be travelling on that wild shore, and who was seen bathing by some young ladies at so great a distance, that not onlygenusbut gender was mistaken. I am acquainted with him, and have had the story from his own mouth. He is a young man, fond of geological pursuits, and one day in the middle of August, having fatigued and heated himself by climbing a rock to examine a particular appearance of granite,he gave his clothes to his Highland guide, who was taking care of his pony, and descended to the sea. The sun was just setting, and he amused himself for some time by swimming from rock to rock, and having unclipped hair and no cap, he sometimes threw aside his locks, and wrung the water from them on the rocks. He happened the year after to be at Harrowgate, and was sitting at table with two young ladies from Caithness, who were relating to a wondering audience the story of the mermaid they had seen, which had already been published in the newspapers: they described her, as she usually is described by poets, as a beautiful animal with remarkably fair skin and long green hair. The young gentleman took the liberty, as most of the rest of the company did, to put a few questions to the elder of the two ladies,—such as, on what day and precisely where this singular phenomenon had appeared. She had noted down not merely the day, but the hour and minute, and produced a map of the place. Our bather referred to his journal, and showed that a human animal was swimming in the very spot at that very time, who had some of the characters ascribed to the mermaid, but who laid no claim to others, particularly the green hair and fish's tail, but, being rather sallow in the face, was glad to have such testimony to the colour of his body beneath his garments."
With this story, I must conclude my review of "Salmonia,"—a work of considerable scientific and popular interest, and which cannot fail to become the favourite companion of the philosophical angler. The only production with which it can be at allcompared is that of the "Complete Angler, by Izaac Walton." I agree with the critic who regards the two authors as pilgrims bound for the same shrine, resembling each other in their general habit—the scalloped hat, the dalmatique, and the knobbed and spiked staff—which equalize all who assume the character; yet, though alike in purpose, dress, and demeanour, the observant eye can doubtless discern an essential difference betwixt those devotees. The burgess does not make his approach to the shrine with the stately pace of a knight or a noble; the simple and uninformed rustic has not the contemplative step of the philosopher, or the quick glance of the poet. The palm of originality and of exquisite simplicity, which cannot perhaps be imitated with entire success, must remain with the common father of anglers—the patriarch Izaac; but it would be absurd to compare his work with the one written by the most distinguished philosopher of the nineteenth century, whose genius, like a sunbeam, illumined every recess which it penetrated, imparting to scarcely visible objects, definite forms and various colours.
If the advanced age of Walton was pleaded by himself as a sufficient reason for procuring "a writ of ease," the friends of Davy may surely claim at the hands of the critic an indulgent reception for a congenial work written in the hour of bodily lassitude and sickness. This benevolent feeling, however, did not penetrate every heart. A passage, which I shall presently quote, appears to have given great offence to the President of the Mechanics'Institute, and to have been considered by him as the indication of a covert hostility to the spread of knowledge. The earth had scarcely closed upon the remains of the philosopher, when, in his anniversary speech,[114]the Autocrat of all the Mechanics, availing himself of this pretext, assailed his character with the charge of "conceit, pride, and arrogance."
The following is the passage in Salmonia, which provoked this angry and unjust philippic.
"I am sorry to say, I think the system carried too far in England. God forbid, that any useful light should be extinguished! let the persons who wish for education receive it; but it appears to me that, in the great cities in England, it is, as it were, forced upon the population; and that sciences, which the lower classes can only very superficially acquire, are presented to them; in consequence of which they often become idle and conceited, and above their usual laborious occupations. The unripe fruit of the tree of knowledge is, I believe, always bitter or sour; and scepticism and discontentment—sicknesses of the mind—are often the result of devouring it."
Methinks I hear the reader exclaim—"How little could Davy imagine that his prophetic words would have been so soon fulfilled!"—But I would seriously recommend to the President of the Mechanics'Institute, an anecdote which, if properly applied, cannot fail to be instructive.—When Diogenes, trampling with his dirty feet on the embroidered couch of Plato, cried out—"Thus do I trample on the pride of Plato!" the philosopher shook his head, and replied—"Truly, but with more pride thou dost it, good Diogenes."
Sir H. Davy's paper on the Phenomena of Volcanoes.—His experiments on Vesuvius.—Theory of Volcanic action.—His reception abroad.—Anecdotes.—His last letter to Mr. Poole from Rome.—His paper on the Electricity of the Torpedo.—Consolations in Travel, or the Last Days of a Philosopher.—Analysis of the work.—Reflections suggested by its style and composition.—Davy and Wollaston compared.—His last illness.—Arrival at Geneva.—His Death.
A short time before Sir Humphry Davy quitted England, to which he was destined never to return, he communicated to the Royal Society a paper "On the Phenomena of Volcanoes;" which was read on the 20th of March 1828, and published in the Transactions of that year.
The object of this memoir was to collect and record the various observations and experiments which he had made on Vesuvius, during his several visits to that volcano. The appearances which it presented in 1814 and 1815 have been already noticed; it was in December 1819, and during the two succeeding months, that the mountain offered a favourable opportunity for making those experiments which form the principal subject of the present communication.
It was a point of great importance to determinewhether any combustion was going on at the moment the lava issued from the mountain; for this fact being once discovered, and the nature of the combustible matter ascertained, we should gain an immense step towards a just theory of the sources of volcanic action. For this purpose, he carefully examined both the lava and the elastic fluids with which it was accompanied. He was unable, however, to detect any thing like deflagration with nitre, which must have taken place had the smallest quantity of carbonaceous matter been present; nor could he, by exposing the ignited mass to portions of atmospheric air, discover that any appreciable quantity of oxygen had been absorbed. On immersing fused lava in water, no decomposition of that fluid followed, so that there could not have existed any quantity of the metallic bases of the alkalies or earths. Common salt, chloride of iron, the sulphates and muriates of potash, and soda, generally constituted the mass of solid products; while steam, muriatic acid fumes, and occasionally sulphurous acid vapours, formed the principal elastic matters disengaged.
He informs us it was on the 26th of January 1820, that he had the honour to accompany his Royal Highness the Prince of Denmark in an excursion to the mountain, on which occasion his friend, Cavalier Monticelli, was also present. At this time, the lava was seen nearly white hot through a chasm near the place where it flowed from the mountain; and yet, although he threw nitre upon it in large quantities through this chasm, there was no more increase of ignition than when the experimentwas made on lava exposed to the free air. He observed that the appearance of the sublimations was very different from that which they had presented on former occasions; those near the aperture were coloured green and blue by salt of copper; but there was, as usual, a great quantity of muriate of iron. On the 5th, the sublimate of the lava was pure chloride of sodium; in the sublimate of January 6th, there were both sulphate of soda and indications of sulphate of potash; but in those which he collected during this last visit, the sulphate of soda was in much larger quantities, and there was much more of a salt of potash.
For nearly three months the craters, of which there were two, were in activity. The larger one threw up showers of ignited ashes and stones to a height apparently of from two hundred to two hundred and fifty feet; and from the smaller crater steam arose with great violence. Whenever the crater could be approached, it was found incrusted with saline matter: and the walk to the edge of the small crater, on the 6th of January, was through a mass of loose saline matter, principally common salt coloured by muriate of iron, in which the foot sunk to some depth. It was easy, even at a great distance, to distinguish between the steam disengaged by one of the craters, and the earthy matter thrown up by the other. The steam appeared white in the day, and formed perfectly white clouds, which reflected the morning and evening light of the purest tints of red and orange. The earthy matter always appeared as a black smoke, forming dark clouds, and in the night it was highly luminous at the moment of the explosion.
He concludes this paper on Volcanoes with some observations on the theory of their phenomena. "It appears," says he, "almost demonstrable, that none of the chemical causes anciently assigned for volcanic fires can be true. Amongst these, the combustion of mineral coal is one of the most current; but it seems wholly inadequate to account for the phenomena. However large the stratum of pit-coal, its combustion under the surface could never produce violent and excessive heat; for the production of carbonic acid gas, when there was no free circulation of air, must tend constantly to impede the process: and it is scarcely possible that carbonaceous matter, if such a cause existed, should not be found in the lava, and be disengaged with the saline or aqueous products from the bocca or craters. There are many instances in England of strata of mineral coal which have been long burning; but the results have been merely baked clay and schists, and it has produced no result similar to lava.
"If the idea of Lemery were correct, that the action of sulphur on iron may be a cause of volcanic fires, sulphate of iron ought to be the great product of the volcano; which is known not to be the case; and the heat produced by the action of sulphur on the common metals is quite inadequate to account for the appearances. When it is considered that volcanic fires occur and intermit with all the phenomena that indicate intense chemical action, it seems not unreasonable to refer them to chemical causes. But for phenomena upon such a scale, an immense mass of matter must be in activity, and the products of the volcano ought to give an idea of the natureof the substances primarily active. Now, what are these products? Mixtures of the earths in an oxidated and fused state, and intensely ignited; water and saline substances, such as might be furnished by the sea and air, altered in such a manner as might be expected from the formation of fixed oxidated matter. But it may be said, if the oxidation of the metals of the earths be the causes of the phenomena, some of these substances ought occasionally to be found in the lava, or the combustion ought to be increased at the moment the materials passed into the atmosphere. But the reply to this objection is, that it is evident that the changes which occasion volcanic fires take place in immense subterranean cavities; and that the access of air to the acting substances occurs long before they reach the exterior surface.
"There is no question but that the ground under the solfaterra is hollow; and there is scarcely any reason to doubt of a subterraneous communication between this crater and that of Vesuvius: whenever Vesuvius is in an active state, the solfaterra is comparatively tranquil. I examined the bocca of the solfaterra on the 21st of February 1820, two days before the activity of Vesuvius was at its height: the columns of steam which usually arise in large quantities when Vesuvius is tranquil, were now scarcely visible, and a piece of paper thrown into the aperture did not rise again; so that there was every reason to suppose the existence of a descending current of air. The subterraneous thunder heard at such great distances under Vesuvius is almost a demonstration of the existence of greatcavities below filled with aëriform matter: and the same excavations which, in the active state of the volcano, throw out, during so great a length of time, immense volumes of steam, must, there is every reason to believe, in its quiet state, become filled with atmospheric air.[115]
"To what extent subterraneous cavities may exist, even in common rocks, is shown in the limestone caverns of Carniola, some of which contain many hundred thousand cubical feet of air; and in proportion as the depth of an excavation is greater, so is the air more fit for combustion.
"The same circumstances which would give alloys of the metals of the earths the power of producing volcanic phenomena, namely, their extreme facility of oxidation, must likewise prevent them from ever being found in a pure combustible state in the products of volcanic eruptions; for before they reach the external surface, they must not only be exposed to the air in the subterranean cavities, but be propelled by steam; which must possess, under the circumstances, at least the same facility of oxidating them as air. Assuming the hypothesis of the existence of such alloys of the metals of the earths as may burn into lava in the interior, the whole phenomena may be easily explained from the action of the water of the sea and air on those metals; nor is there any fact, or any of the circumstanceswhich I have mentioned in the preceding part of this paper, which cannot be easily explained according to that hypothesis. For almost all the volcanoes in the old world of considerable magnitude are near, or at no considerable distance from the sea: and if it be assumed that the first eruptions are produced by the action of sea-water upon the metals of the earths, and that considerable cavities are left by the oxidated metals thrown out as lava, the results of their action are such as might be anticipated; for, after the first eruptions, the oxidations which produce the subsequent ones may take place in the caverns below the surface; and when the sea is distant, as in the volcanoes of South America, they may be supplied with water from great subterranean lakes, as Humboldt states that some of them throw up quantities of fish.
"On the hypothesis of a chemical cause for volcanic fires, and reasoning from known facts, there appears to me no other adequate source than the oxidation of the metals which form the bases of the earths and alkalies; but it must not be denied, that considerations derived from thermometrical experiments on the temperature of mines and of sources of hot water, render it probable that the interior of the globe possesses a very high temperature: and the hypothesis of the nucleus of the globe being composed of fluid matter offers a still more simple solution of the phenomena of volcanic fires than that which has been just developed."
It must be admitted that the concluding sentence of this memoir is rather equivocal. He states that the metalloidal theory of volcanoes is most chemical,but that the hypothesis which assumes the high temperature of the interior of the globe is the most simple; but he leaves us in doubt as to his own belief upon the subject. In his "Last Days," however, we shall find that he offers a less reserved opinion upon this question.
With respect to Sir Humphry Davy's last journey to Rome, I have nothing of particular interest to relate. Universally known and respected, a member of almost every scientific society in Europe, there was not a part of the Continent in which he felt as a stranger in a foreign land. I might, in addition to the circumstances which have been already mentioned, relate several anecdotes in proof of the widely-extended popularity which his genius and discoveries had secured for him. The following striking incidents deserve particular notice.—Whilst sporting in Austria, he was assaulted by some peasants; and the outrage was no sooner made known to the Emperor, than he expressed his sorrow and indignation in the strongest language, and immediately directed that a party of troops should surround the district, and a most rigorous search be made for the culprits. The search was of course successful, and the "Carinthian boors" received merited chastisement.
For the following anecdote I am indebted to Lady Davy. Her Ladyship was travelling alone, on account of ill health, and upon arriving at Basle, she naturally felt a strong desire to visit its far-famed library; it so happened, however, that Sunday wasthe only day which afforded her this opportunity, and so strictly is the sabbath observed at that place, that she was at once informed that an admission to the library, under any circumstances, was altogether impossible. She nevertheless addressed a note to the librarian, stating to him her name, and the reasons for her unusual request. He immediately returned an answer, and appointed the hour of ten for her visit. Having shown her all that deserved inspection, he concluded his attentions by saying, "Madam, I have held the keys of this library for thirty years, during which period only three persons have been admitted to see its treasures on the Sunday; two of these were crowned heads, the third the wife of the most celebrated philosopher in Europe."
The following is the last letter which Davy ever wrote to his much-valued friend Mr. Poole.—
TO THOMAS POOLE, ESQ.Rome, Feb. 6, 1829.MY DEAR POOLE,I have not written to you during my absence from England, because I had no satisfactory account of any marked progress towards health to give you, and the feelings of an invalid are painful enough for himself, and should, I think, never form a part of his correspondence; for they are not diminished by the conviction that they are felt by others. Would I were better! I would then write to you an agreeable letter from this glorious city; but I am herewearing awaythe winter; a ruin amongst ruins! I am anxious to hear from you,—very anxious, so pray write to me with this address, "Sir H. Davy, Inglese, posta restanti, Rovigo,Italia." You know you must pay the postage to the frontier, otherwise the letters, like one a friend sent to me, will go back to you. Pray be so good as to be particular in the direction,—the "Inglese" is necessary. I hope you got a copy of my little trifle "Salmonia." I ordered copies to be sent to you, to Mr. W——, and to Mr. Baker: but as the course of letters in foreign countries is uncertain, I am not sure you received them; if not, you will have lost little; asecond editionwill soon be out, which will be in every respect more worthy of your perusal, being, I think, twice (not saying much for it) as entertaining and philosophical. I will take care by early orders that you have this book. I write and philosophize a good deal, and have nearly finished a work with a higher aim than the little book I speak of above, and which I shall dedicate to you. It contains the essence of my philosophical opinions, and some of my poetical reveries. It is, like the "Salmonia," an amusement of my sickness; but "paulo majora canamus." I sometimes think of the lines of Waller, and seem to feel their truth:"The soul's dark cottage, batter`d and decay'd,Lets in new lights through chinks that Time has made."I have, notwithstanding my infirmities, attended to scientific objects whenever it was in my power, and I have sent the Royal Society a paper which they will publish, on the peculiar Electricity of the Torpedo, which I think bears remotely upon the functions of life. I attend a good deal to Natural History, and I think I have recognised in the Mediterranean anew species of eel, a sort of link betweenthe conger and the muræna of the ancients. I have no doubt Mr. Baker is right about the distinction between the conger and the common eel. I am very anxious to hear what he thinks abouttheir generation. Pray get from him a distinct opinion on this subject. I am at this moment getting theeels in the marketshere dissected, and have foundovain plenty. Pray tell me particularly what Mr. Baker has done; this is a favourite subject with me, and you can give me no news so interesting. My dear friend, I shall never forget your kindness to me. You, with one other person, have given me the little happiness I have enjoyed since my severe visitation.I fight against sickness and fate, believing I have still duties to perform, and that even my illness is connected in some way with my being made useful to my fellow-creatures. I have this conviction full on my mind, that intellectual beings spring from the same breath of Infinite Intelligence, and return to it again, but by different courses. Like rivers, born amidst the clouds of heaven, and lost in the deep and eternal ocean—some in youth, rapid and short-lived torrents; some in manhood, powerful and copious rivers; and some in age, by a winding and slow course, half lost in their career, and making their exit through many sandy and shallow mouths. I hope to be at Rovigo about the first week in April. I travel slowly and with my own horses. If you will come and join me there, I can give you a place in a comfortable carriage, and can show you the most glorious country in Europe—Illyria and Styria, and take you to the French frontier before the beginning of autumn,—perhaps to England. Ifyou can come, do so at once. I have two servants, and can accommodate you with every thing. I think of taking some baths before I return, in Upper Austria; but I write as if I were a strong man, when I am like a pendulum, as it were, swinging between death and life.God bless you, my dear Poole.Your grateful and affectionate friend,H. Davy.Pray remember me to our friends at Stowey.
TO THOMAS POOLE, ESQ.
Rome, Feb. 6, 1829.
MY DEAR POOLE,
I have not written to you during my absence from England, because I had no satisfactory account of any marked progress towards health to give you, and the feelings of an invalid are painful enough for himself, and should, I think, never form a part of his correspondence; for they are not diminished by the conviction that they are felt by others. Would I were better! I would then write to you an agreeable letter from this glorious city; but I am herewearing awaythe winter; a ruin amongst ruins! I am anxious to hear from you,—very anxious, so pray write to me with this address, "Sir H. Davy, Inglese, posta restanti, Rovigo,Italia." You know you must pay the postage to the frontier, otherwise the letters, like one a friend sent to me, will go back to you. Pray be so good as to be particular in the direction,—the "Inglese" is necessary. I hope you got a copy of my little trifle "Salmonia." I ordered copies to be sent to you, to Mr. W——, and to Mr. Baker: but as the course of letters in foreign countries is uncertain, I am not sure you received them; if not, you will have lost little; asecond editionwill soon be out, which will be in every respect more worthy of your perusal, being, I think, twice (not saying much for it) as entertaining and philosophical. I will take care by early orders that you have this book. I write and philosophize a good deal, and have nearly finished a work with a higher aim than the little book I speak of above, and which I shall dedicate to you. It contains the essence of my philosophical opinions, and some of my poetical reveries. It is, like the "Salmonia," an amusement of my sickness; but "paulo majora canamus." I sometimes think of the lines of Waller, and seem to feel their truth:
"The soul's dark cottage, batter`d and decay'd,Lets in new lights through chinks that Time has made."
"The soul's dark cottage, batter`d and decay'd,Lets in new lights through chinks that Time has made."
"The soul's dark cottage, batter`d and decay'd,Lets in new lights through chinks that Time has made."
"The soul's dark cottage, batter`d and decay'd,
Lets in new lights through chinks that Time has made."
I have, notwithstanding my infirmities, attended to scientific objects whenever it was in my power, and I have sent the Royal Society a paper which they will publish, on the peculiar Electricity of the Torpedo, which I think bears remotely upon the functions of life. I attend a good deal to Natural History, and I think I have recognised in the Mediterranean anew species of eel, a sort of link betweenthe conger and the muræna of the ancients. I have no doubt Mr. Baker is right about the distinction between the conger and the common eel. I am very anxious to hear what he thinks abouttheir generation. Pray get from him a distinct opinion on this subject. I am at this moment getting theeels in the marketshere dissected, and have foundovain plenty. Pray tell me particularly what Mr. Baker has done; this is a favourite subject with me, and you can give me no news so interesting. My dear friend, I shall never forget your kindness to me. You, with one other person, have given me the little happiness I have enjoyed since my severe visitation.
I fight against sickness and fate, believing I have still duties to perform, and that even my illness is connected in some way with my being made useful to my fellow-creatures. I have this conviction full on my mind, that intellectual beings spring from the same breath of Infinite Intelligence, and return to it again, but by different courses. Like rivers, born amidst the clouds of heaven, and lost in the deep and eternal ocean—some in youth, rapid and short-lived torrents; some in manhood, powerful and copious rivers; and some in age, by a winding and slow course, half lost in their career, and making their exit through many sandy and shallow mouths. I hope to be at Rovigo about the first week in April. I travel slowly and with my own horses. If you will come and join me there, I can give you a place in a comfortable carriage, and can show you the most glorious country in Europe—Illyria and Styria, and take you to the French frontier before the beginning of autumn,—perhaps to England. Ifyou can come, do so at once. I have two servants, and can accommodate you with every thing. I think of taking some baths before I return, in Upper Austria; but I write as if I were a strong man, when I am like a pendulum, as it were, swinging between death and life.
God bless you, my dear Poole.Your grateful and affectionate friend,H. Davy.
Pray remember me to our friends at Stowey.
His paper on the Electricity of the Torpedo, to which he alludes in the foregoing letter, appears to have been written shortly after he had finished his "Salmonia," as it is dated from Lubiana, Illyria, on the 24th of October, and it was read before the Royal Society on the 20th of November 1828, and published in the first part of the Transactions for 1829. It will be remembered, that this subject had long engaged his attention; and he expresses his surprise that the electricity of living animals should not have been an object of greater attention, both on account of its physiological importance, and its general relation to the science of electro-chemistry.
When Volta discovered his wonderful pile, he imagined he had made a perfect resemblance of the organ of the Gymnotus and Torpedo; and Davy observes, that whoever has felt the shocks of the natural and artificial instruments must have been convinced, as far as sensation is concerned, of their strict analogy.
After the discovery of thechemicalpower of the Voltaic instrument, he was naturally desirous ofascertaining whether this property was possessed by the electrical organs of living animals; for which purpose, he instituted various experiments, but he could not discover that such was the fact. Upon mentioning his researches to Signor Volta, with whom he passed some time in the summer of 1815, the Italian philosopher showed him a peculiar form of his instrument, which appeared to fulfil the conditions of the organs of the torpedo;viz.a pile, of which the fluid substance was a very imperfect conductor, such as honey or a strong saccharine extract, which required a certain time to become charged, and which did not decompose water, though it communicated weak shocks.
The discovery by Oersted of the effects of Voltaic electricity on the magnetic needle induced Davy to examine whether the electricity of living animals possessed a similar power. Having, after some trouble, procured two lively and recently caught Torpedoes, he passed the shocks from the largest of these animals a number of times through the circuit of an extremely delicate magnetic electrometer, but, although every precaution was used, not the slightest deviation of, or effect on, the needle could be perceived.
"These negative results," says he, "may be explained by supposing that the motion of the electricity in the torpedinal organ is in no measurable time, and that a current of some continuance is necessary to produce the deviation of the magnetic needle; and I found that the magnetic electrometer was equally insensible to the weak discharge of a Leyden jar as to that of the torpedinal organ;though whenever there was a continuous current from the smallest surfaces in Voltaic combinations of the weakest power, but in which some chemical action was going on, it was instantly and powerfully affected. Two series of zinc and silver, and paper moistened in salt and water, caused the permanent deviation of the needle several degrees, though the plates of zinc were only one-sixth of an inch in diameter.
"It would be desirable to pursue these enquiries with the electricity of the Gymnotus, which is so much more powerful than that of the Torpedo; but if they are now to be reasoned upon, they seem to show a stronger analogy between common and animal electricity, than between Voltaic and animal electricity; it is however, I think, more probable that animal electricity will be found of a distinctive and peculiar kind.
"Common electricity is excited upon non-conductors, and is readily carried off by conductors and imperfect conductors. Voltaic electricity is excited upon combinations of perfect and imperfect conductors, and is only transmitted by perfect conductors, or imperfect conductors of the best kind.
"Magnetism, if it be a form of electricity, belongs only to perfect conductors; and, in its modifications, to a peculiar class of them.
"The animal electricity resides only in the imperfect conductors forming the organs of living animals, and its object in the economy of nature is to act on living animals.
"Distinctions might be established in pursuing the various modifications or properties of electricityin these different forms; but it is scarcely possible to avoid being struck by another relation of this subject. The torpedinal organ depends for its powers upon the will of the animal. John Hunter has shown how copiously it is furnished with nerves. In examining the columnar structure of the organ of the Torpedo, I have never been able to discover arrangements of different conductors similar to those in galvanic combinations, and it seems not improbable that the shock depends upon some property developed by the action of the nerves.
"To attempt to reason upon any phenomena of this kind as dependent upon a specific fluid would be wholly vain. Little as we know of the nature of electrical action, we are still more ignorant of the nature of the functions of the nerves. There seems, however, a gleam of light worth pursuing in the peculiarities of animal electricity,—its connexion with so large a nervous system, its dependence upon the will of the animal, and the instantaneous nature of its transfer, which may lead, when pursued by adequate enquirers, to results important for physiology."
He concludes this paper by expressing his fear that the weak state of his health will prevent him from following the subject with the attention it seems to deserve; and he therefore communicates these imperfect trials to the Royal Society, in the hope that they may lead to more extensive and profound researches.
We come now to the consideration of the last production of his genius—"Consolations in Travel, or the Last Days of a Philosopher:" A work which, he informs us in the preface, was composed immediatelyafter Salmonia, under the same unfavourable and painful circumstances, and at a period when his constitution suffered from new attacks. From this exercise of the mind, he tells us, that he derived some pleasure and some consolation, when most other sources of consolation and pleasure were closed to him; and he ventures to hope that those hours of sickness may be not altogether unprofitable to persons in perfect health. His brother, Dr. Davy, who edited the work after the decease of Sir Humphry, informs us that it was concluded at the very moment of the invasion of the author's last illness, and that, had his life been prolonged, it is probable some additions and some changes would have been made.
"The characters of the persons of the dialogue," continues the Editor, "were intended to be ideal, at least in great part;—such they should be considered by the reader; and it is to be hoped, that the incidents introduced, as well as the persons, will be viewed only as subordinate and subservient to the sentiments and the doctrines. The dedication, it may be specially noticed, is the Author's own, and in the very words dictated by himself at a time when he had lost the power of writing, except with extreme difficulty, owing to the paralytic attack, although he retained in a very remarkable manner all his mental faculties unimpaired and unclouded." The words of the Dedication are "To Thomas Poole, Esq.of Nether Stowey; in remembrance of thirty years of continued and faithful friendship."
This is a most extraordinary and interesting work: extraordinary, not only from the wild strength of itsfancy, and the extravagance of its conceptions, but from the bright light of scientific truth which is constantly shining through its metaphorical tissue, and irradiating its most shadowy imaginings. It may be compared to the tree of the lower regions in the Æneid, to every leaf of which was attached a dream; and yet, however wildly his fancy may dream, his philosophy never sleeps; and in his exit from the land of phantoms, the author can in no instance be accused of having mistaken the gate of ivory for that of horn. To the biographer, the work is of the highest interest and value, by confirming, in a remarkable manner, the opinion so frequently expressed in the course of these memoirs, with respect to the diversified talents of Sir Humphry Davy; and above all, by elucidating that rare combination of imagination with judgment, which imparted to his genius its more striking peculiarities.
The work consists of six Dialogues:—1. The Vision; 2. Discussions connected with the Vision in the Colosæum; 3. The Unknown; 4. The Proteus, or Immortality; 5. The Chemical Philosopher; and6. Pola, or Time.
The interlocutors of the first dialogue are two intellectual Englishmen, one of whom the author callsAmbrosio; a man of highly cultivated taste, great classical erudition, and minute historical knowledge: a Catholic in religion, but so liberal in his sentiments, that in another age he might have been secretary to Ganganelli. The other friend, whom he callsOnuphrio, was a man of a very different character: belonging to the English aristocracy, he had some of the prejudices usually attached to birthand rank; but his manners were gentle, his temper good, and his disposition amiable. Having been partly educated at a northern university in Britain, he had adopted views in religion which went even beyond toleration, and which might be regarded as entering the verge of scepticism. For a patrician, he was very liberal in his political views. His imagination was poetical and discursive, his taste good, and his tact extremely fine,—so exquisite, indeed, that it sometimes approached to morbid sensibility, and disgusted him with slight defects, and made him keenly sensible of small perfections to which common minds have been indifferent.
The author, with these his two friends, makes an excursion to the Colosæum, and the conversation, which a view of those magnificent ruins produced, together with the account of a dream, or vision, which occurred to him while left alone amidst these mouldering monuments, forms the subject-matter of the first dialogue. It is impossible for any person of the least imagination to contemplate this decay of former magnificence without strong emotion; but the direction and tone of such feeling will be necessarily modified by the qualities of the mind in which it is excited; and the author has therefore very properly assigned to each of thedramatis personæ, such opinions as might best correspond with his character and temperament.
They are all represented as being struck with the transiency of human monuments; butAmbrosioviews with triumph the sanctifying influence of a few crosses planted around the ruins, in arrestingthe farther decay of the pile. "Without the influence of Christianity," he exclaims, "these majestic ruins would have been dispersed or levelled to the dust. Plundered of their lead and iron by the barbarians, Goths and Vandals, and robbed even of their stones by Roman princes—the Barberini, they owe what remains of their relics to the sanctifying influence of that faith which has preserved for the world all that was worth preserving, not merely arts and literature, but likewise that which constitutes the progressive nature of intellect, and the institutions which afford to us happiness in this world, and hopes of a blessed immortality in the next." And he continues,—"What a contrast the present application of this building, connected with holy feelings and exalted hopes, is to that of the ancient one, when it was used for exhibiting to the Roman people the destruction of men by wild beasts, or of men more savage than wild beasts by each other, to gratify a horrible appetite for cruelty, founded upon a still more detestable lust, that of universal domination! And who would have supposed, in the time of Titus, that a faith, despised in its insignificant origin, and persecuted from the supposed obscurity of its founder and its principles, should have reared a dome to the memory of one of its humblest teachers, more glorious than was ever framed for Jupiter or Apollo in the ancient world, and have preserved even the ruins of the temples of the Pagan deities, and have burst forth in splendour and majesty, consecrating truth amidst the shrines of error, employing the idols of the Roman superstition for the most holy purposes,and rising a bright and constant light amidst the dark and starless night which followed the destruction of the Roman empire!"
It was not to be expected thatOnuphrio, whose views are represented as verging upon scepticism, should have tacitly coincided in these opinions ofAmbrosio. He admits, indeed, that some little of the perfect state in which these ruins exist may have been owing to the causes just described; but these causes, he maintains, have only lately begun to operate, and the mischief was done before Christianity was established at Rome. "Feeling differently on these subjects," says he, "I admire this venerable ruin rather as the record of the destruction of the power of the greatest people that ever existed, than as a proof of the triumph of Christianity; and I am carried forward, in melancholy anticipation, to the period when even the magnificent dome of St. Peter's will be in a similar state to that in which the Colosæum now is, and when its ruins may be preserved by the sanctifying influence of some new and unknown faith; when perhaps the statue of Jupiter, which at present receives the kiss of the devotee, as the image of St. Peter, may be employed for another holy use, as the personification of a future saint or divinity; and when the monuments of the Papal magnificence shall be mixed with the same dust as that which now covers the tombs of the Cæsars.
"Such, I am sorry to say, is the general history of all the works and institutions belonging to humanity. They rise, flourish, and then decay and fall; and the period of their decline is generallyproportional to that of their elevation. In ancient Thebes or Memphis, the peculiar genius of the people has left us monuments from which we can judge of their arts, though we cannot understand the nature of their superstitions. Of Babylon and of Troy, the remains are almost extinct; and what we know of those famous cities is almost entirely derived from literary records. Ancient Greece and Rome we view in the few remains of their monuments; and the time will arrive when modern Rome shall be what ancient Rome now is; and ancient Rome and Athens will be what Tyre or Carthage now are, known only by coloured dust in the desert, or coloured sand, containing the fragments of bricks, or glass, washed up by the wave of a stormy sea."
For this desponding view of passing events,Onuphriofinds consolation in the evidences of revealed religion. In the origin, progress, elevation, decline, and fall of the empires of antiquity, he sees proofs that they were intended for a definite end in the scheme of human redemption; and he finds prophecies which have been amply verified. He regards the foundation or the ruin of a kingdom, which appears in civil history so great an event, as comparatively of small moment in the history of man and in his religious institutions. He considers the establishment of the worship of one God amongst a despised and contemned people, as the most important circumstance in the history of the early world. He regards the Christian dispensation as naturally arising out of the Jewish, and the doctrines of the Pagan nations all preparatory to thetriumph and final establishment of a creed fitted for the most enlightened state of the human mind, and equally adapted to every climate and every people."
We cannot but regard these passages with great interest, as indicating the train of thought which must have occupied the mind of their author, and as proving that, in his latter days, he not only studied the doctrines of Christianity, but derived the greatest consolation from its tenets.
After some farther conversation,OnuphrioandAmbrosioleave their friend the author to pursue his meditations amidst the solitude of the ruins.
Seated in the moonshine on one of the steps leading to the seats supposed to have been occupied by the patricians in the Colosæum at the time of the public games, the train of ideas in which he had before indulged continued to flow with a vividness and force increased by the stillness and solitude of the scene, and by the full moon, which, he observes, has always a peculiar effect on these moods of feeling in his mind, giving to them a wildness and a kind of indefinite sensation, such as he supposes belong at all times to the true poetical temperament.
"It must be so," thought he, "no new city will rise again out of the double ruins of this; no new empire will be founded upon these colossal remains of that of the old Romans. The world, like the individual, flourishes in youth, rises to strength in manhood, falls into decay in age; and the ruins of an empire are like the decrepid frame of an individual, except that they have some tints of beauty, which nature bestows upon them. The sun of civilization arose in the East, advanced towards theWest, and is now at its meridian; in a few centuries more, it will probably be seen sinking below the horizon, even in the new world; and there will be left darkness only where there is a bright light, deserts of sand where there were populous cities, and stagnant morasses where the green meadow, or the bright corn-field once appeared. Time," he exclaimed, "which purifies, and, as it were, sanctifies the mind, destroys and brings into utter decay the body; and even in nature its influence seems always degrading. She is represented by the poet as eternal in her youth; but amongst these ruins she appears to me eternal in her age, and here, no traces of renovation appear in the ancient of days."
He had scarcely concluded this ideal sentence, when his reverie became deeper, and his imagination called up a spirit, who, having rebuked him for his ignorance and presumption, undeceives him in his views of the history of the world, by unfolding to him in a vision the progress of man from a state of barbarity to that of high civilization. He is first shown a country covered with forests and marshes; wild animals were grazing in large savannahs, and carnivorous beasts, such as lions and tigers, occasionally disturbing and destroying them. Man appeared as a naked savage, feeding upon wild fruits, or devouring shell-fish, or fighting with clubs for the remains of a whale which had been thrown upon the shore. His habitation was a cave in the earth—"See the birth of Time!" exclaimed the Genius; "look at man in his newly-created state, full of youth and vigour. Do you see aught in this state to admire or envy?"
In the next scene, a country opened upon his view, which appeared partly wild and partly cultivated; and men were seen covered with the skins of animals, and driving cattle to enclosed pastures; others were reaping and collecting corn, and others again were making it into bread. Cottages appeared furnished with many of the conveniences of life. The Genius now said, "Look at these groups of men who are escaped from the state of infancy; they owe their improvement to a few superior minds still amongst them. That aged man whom you see with a crowd around him taught them to build cottages; from that other they learnt to domesticate cattle; from others, to collect and sow corn and seeds of fruit. And these arts will never be lost; another generation will see them more perfect. You shall be shown other visions of the passages of time; but as you are carried along the stream which flows from the period of creation to the present moment, I shall only arrest your transit to make you observe some circumstances which will demonstrate the truths I wish you to know." He then proceeds to describe in succession the different scenes as they appeared before him, and to relate the observations by which his genius, or intellectual guide, accompanied him.
A great extent of cultivated plains, large cities on the sea-shore, palaces, forums, and temples, were displayed before him. He saw men associated in groups, mounted on horses, and performing military exercises; galleys moved by oars on the ocean; roads intersecting the country covered with travellers,and containing carriages moved by men or horses. The Genius now said, "You see the early state of civilization of man: the cottages of the last race you beheld have become improved into stately dwellings, palaces, and temples, in which use is combined with ornament. The few men to whom, as I said before, the foundations of these improvements were owing, have had divine honours paid to their memory. But look at the instruments belonging to this generation, and you will find they were only of brass. You see men who are talking to crowds around them, and others who are apparently amusing listening groups by a kind of song or recitation; these are the earliest bards and orators; but all their signs of thought are oral, for written language does not yet exist."
The Genius next presented to him a scene of varied business and imagery. He saw a man who bore in his hands the same instruments as our modern smiths, presenting a vase, which appeared to be made of iron, amidst the acclamations of an assembled multitude; and he saw in the same place men who carried rolls of papyrus in their hands, and wrote upon them with reeds containing ink, made from the soot of wood mixed with a solution of glue.—"See," the Genius said, "an immense change produced in the condition of society by the two arts of which you now see the origin; the one, that of rendering iron malleable, which is owing to a single individual, an obscure Greek; the other, that of making thought permanent in written characters,—an art which has gradually arisen from the hieroglyphicswhich you may observe on yonder pyramids. You will now see human life more replete with power and activity."
In the scenes that succeeded, he saw bronze instruments thrown away; malleable iron converted into hard steel, and applied to a thousand purposes of civilized life; bands of men traversing the sea, founding colonies, building cities, and, wherever they established themselves, carrying with them their peculiar arts. He saw the Roman world succeeded by cities filled with an idle and luxurious population, and the farms which had been cultivated by warriors, who left the plough to take the command of armies, now in the hands of slaves; and the militia of free men supplanted by bands of mercenaries, who sold the Empire to the highest bidder. He saw immense masses of warriors collecting in the North and East, carrying with them no other proofs of cultivation but their horses and steel arms. He saw these savages every where plundering cities and destroying the monuments of arts and literature. Ruin, desolation, and darkness were before him, and he closed his eyes to avoid the melancholy scene. "See," said the Genius, "the termination of a power believed by its founders invincible, and intended to be eternal. But you will find, though the glory and greatness belonging to its military genius have passed away, yet those belonging to the arts and institutions by which it adorned and dignified life, will again arise in another state of society."
Upon again opening his eyes, he saw Italy recovering from her desolation, towns arising withgovernments almost upon the model of ancient Athens and Rome, and these different small states rivals in arts and arms;—he saw the remains of libraries, which had been preserved in monasteries and churches by a holy influence, which even the Goth and Vandal respected, again opened to the people;—he saw Rome rising from her ashes, the fragments of statues found amidst the ruins of her palaces and imperial villas, becoming the models for the regeneration of art;—he saw magnificent temples raised in this city, become the metropolis of a new and Christian world, and ornamented with the most brilliant master-pieces of the arts of design.—"Now," the Genius said, "society has taken its modern and permanent aspect. Consider for a moment its relations to letters and to arms, as contrasted with those of the ancient world." He looked, and he saw that, in the place of the rolls of papyrus, libraries were now filled with books. "Behold," the Genius said, "The Printing Press! By the invention of Faust, the productions of genius are, as it were, made imperishable, capable of indefinite multiplication, and rendered an unalienable heritage of the human mind. By this art, apparently so humble, the progress of society is secured, and man is spared the humiliation of witnessing again scenes like those which followed the destruction of the Roman Empire. Now look to the warriors of modern times; you see the spear, the javelin, and the cuirass are changed for the musket and the light artillery. The German monk who discovered gunpowder did not meanly affect the destinies of mankind; wars are become less bloodyby becoming less personal; mere brutal strength is rendered of comparatively little avail; all the resources of civilization are required to move a large army; wealth, ingenuity, and perseverance become the principal elements of success; civilized man is rendered in consequence infinitely superior to the savage, and gunpowder gives permanence to his triumph, and secures the cultivated nations from being ever again overrun by the inroads of millions of barbarians."[116]
The Genius then directs his attention to scenes in which are displayed the triumphs of modern science; such as the steam-engine, and the thousand resources furnished by the chemical and mechanical arts; and she concludes by endeavouring to impress upon him the conviction, "That the results of intellectual labour, or of scientific genius, are permanent, and incapable of being lost. Monarchs change their plans, governments their objects, a fleet or an army effect their purpose and then pass away; but a piece of steel touched by the magnet preserves its character for ever, and secures to man the dominion of the trackless ocean. A new period of society maysend armies from the shores of the Baltic to those of the Euxine, and the empire of the followers of Mahomet may be broken in pieces by a Northern people, and the dominion of the Britons in Asia may share the fate of Tamerlane or Zengis-khan; but the steam-boat which ascends the Delaware, or the St. Lawrence, will be continued to be used, and will carry the civilization of an improved people into the deserts of North America, and into the wilds of Canada. In the common history of the world, as compiled by authors in general, almost all the great changes of nations are confounded with changes in their dynasties, and events are usually referred either to sovereigns, chiefs, heroes, or their armies, which do, in fact, originate from entirely different causes, either of an intellectual or moral nature."
Having instructed him in the history of man as an inhabitant of the earth, the Genius proceeds to reveal to him the mysteries of spiritual natures, in which the author evidently shows his attachment to the belief that our intellectual essence is destined hereafter to enjoy a higher and better state of planetary existence,[117]drinking intellectual light from a purer source, and approaching nearer to the Infinite and Divine mind. I shall not attempt to follow him and his Genius to the verge of the solar system,witnessing in his career the inhabitants of planets and comets. We may upon this occasion truly apply to the author the words of Lucretius—