Imágenes de páginas

atmosphere, having for center the magnetic pole. By transmitting through a rarified gas an electrical discharge around the pole of a strong magnet, he caused a luminous ring to appear, animated with a movement of rotation around this same pole. This experiment is so beautiful that it must be admired even by those physicists, now few in number, who consider that the aurora is derived from a source far beyond the terrestrial atmosphere, and attribute to it a cosmical origin. He writes thus to me, only a short time before the attack of illness which caused his death: "Assist me in defending a theory, which I believe to be founded upon incontestable facts, and which was advocated by Franklin and Arago when there was less evidence in its favor. The investigators who study only the brilliant and occasional auroras of our latitudes, should also take into consideration those less radiant that appear almost every day in the polar regions. I do not know a single observer, placed in our extreme northern countries, who does not support the views I have adopted. Surely it is much in their favor that they are advocated by men who live in the midst of the phenomena; and shall we abandon them because they are opposed by those who witness these remarkable appearances only occasionally, and under the influence of surprise and astonishment which must more or less affect the judgment concerning them ?"

At the equator, the silent magnetic agitations are replaced by electrical storms, accompanied by thunder and rain, marking, so to say, the course of the sun; and if there is a constant manifestation of auroral phenomena, more or less distinct at each pole, there is always an orange tint, of greater or less intensity, at some point of the equator. What purpose do they serve, these electric manifestations, continually exhibited throughout the atmosphere of the earth? We are not yet in a condition to say, but De La Rive has thrown much light upon the question.

When, a hundred years ago, Priestley discovered oxygen, the agent of combustion and respiration, medicine found a valuable auxiliary, and enthusiasts saw in it a means of prolonging life. The experiments of M. Bert, however, proved that this vital air, if inhaled into the lungs in a pare state, was a mortal poison. This same oxygen, as soon as it is electrized, shows that it is accompanied by a very odorous substance, blackening colored bodies, irritating violently the respiratory organs, and converting animal products into saltpeter. This is the ozone M Schönbein, the celebrated professor of Basle, found at times in the atmosphere, particularly when the latter was electrized by thunderclouds. Auguste De La Rive and his learned friend M. de Marignac maintained that ozone is a modification of oxygen, a conclusion rendered incontestable by our two eminent associates, MM. Frémy and Becquerel, jr.

If pure oxygen is deadly in its effects, mingled with the air that surrounds us, it supports life; and if oxygen, ozenized, is a poison, in moderate doses, it purifies the air and fertilizes the soil broken by the plow, giving to its products their agricultural significance.

If it is chance that provides the atmosphere with only just enough of this useful yet dangerous oxygen to support respiration; that brings into being ozone to destroy the deleterious influences which threaten our lives, and to prepare the nourishment necessary for the plants which supply us with food ; if it is this same chance which fixes the limits to the concentration of oxygen, rendering almost immutable the quantity of inert gas mingled in the air that we breathe; which renders possible and durable for centuries the existence of man upon the earth, theu we must conclude, with Auguste De La Rive, that chance is very intelligent; indeed, so intelligent as to deserve another name.

A flourishing industry, which was commenced about thirty-five years ago, under the auspices of the Academy of Sciences—that is, electroplating-originated in the experiments and practical applications of our respected associate. Up to that time the only mode known of gilding bronze was by the use of mercury. This process produced a good and solid surface, but was fatal to the workmen, as their hands were brought in contact with the dangerous metal, and their lungs exposed to the action of the mercurial vapors during the heating of the articles to be gilded. The old academy offered a prize to any one who would obviate the danger attached to this industry, but it was unclaimed. The pres. ent academy was more fortunate. But, if the industry is ivdebted for its stimulation to the galvanic process, we should not forget that the first pieces gilded by electricity came from the hands of the sagacious and disinterested physicist whose labors we are contemplating. Thanks especially to him, we are spared the distressing spectacle formerly presented by hundreds of unfortunate workmen, in voluntary witnesses of the deleterious effects of mercury, who, trembling in every limb, were diseased alike in mind and body.

Auguste De La Rive was a lover and patron of the fine arts, and it was in some sort under his direction that the celebrated painter of Alpine scenery, Calame, executed his chef-d'oeuvre, Mount Rose, the most beauti. ful ornament of the parlor of the scientist. It represents a rugged, lonely scene, a high plateau in the mountains, without verdure or any trace of the presence of man. In the background is the Alps, in the foreground a small, dark lake and some rocks; that is all. But it is nature in her majesty, flooded with the light and enveloped in the pure transparent atmosphere of the mountains—an unadorned exhibition of her grandeur, affecting powerfully the imagination.

Our philosopher was never tired of the beautiful spectacle presented by the effect of the setting sun upon Mont Blanc, and was led to some interesting scientific observations of the phenomenon through his admiration of its picturesque aspect. At the moment when the sun disappears from the horizon, the valley is covered with shade, and the mountain is gradually obscured from the base to near the summit. Tbis alone, for some time, remains illuminated, and, suddenly, while the rest of earth sinks into deeper shadow, takes a bright orange tint, sometimes a bloody or fiery red, and appears like an immense meteor, fixed, incandescent, not belonging to earth, but suspended in the sky. Soon the everincreasing sbade invades even this icy pinnacle. Its outlines grow indistinct, and its color fades to a cadaverous hue. Like the change from life to death in the human face is this rapid transformation from the brilliant tints of departing day to the livid tone which follows upon the forehead of this giant of rock and snow. No one can witness the solemn spectacle for the first time without profound emotion; and the instinctive silence that falls upon the spectator is like the prelude to a prayer. As be turns sorrowfully away, and asks if all is over, suddenly, as if in answer, the mountain is colored anew with a pale rose tint, the reflection of its former splendor. Is the colossus about to revive! No; this fugitive tint is soon effaced, and darkness covers the scene.

The rosy glow, the day's farewell to the snow-clad peaks of these high mountains, is only the reproduction in a particular form of the general effects of the setting sun upon clouds. But what is the cause of the second coloration ? Our associate, after many observations of the summit of Mont Blanc, most frequently subjected to the phenomenon, attributed it to the reflection of the last red rays from vaporous strata accumulated in the up. per regions of the atmosphere. He studied the nature of these vapors, and invented an apparatus for measuring the variations in the transparency of the atmosphere, which are closely observed by the mountaineers, as they judge from them what weather to expect. If the air is perfectly clear, and distant objects plainly visible, the mountains seeming close to the observer, and the sky of a deep blue color, they will tell you that rain is near, though there may be no other sign of its approach. If the weather is decidedly fine, the air is not perfectly clear, but is pervaded by a bluish vapor, the sky is moderately blue, and mountains seem far away.

Auguste De La Rive supposed that these vapors, characteristic of fine weather, were composed of mineral and organic partieles, which float in the air as long as they are dry, but fall to the ground when surcharged with moisture. They are so abundant, that they take from the air its transparency, which is restored when they disappear. The insects which buzz about us are governed by the same law. If the swallows fly close to the ground at the approach of rain, and high up in the air in fine weather, it is because in the first case the insects upon which they feed are weighed down by moisture, while, in the second, relieved of this burden, they mount higher into space.

The ardor of Auguste De La Rive for the study of electricity could not be satisfied with only the labors of the laboratory. He conceived the plan of a work wbich would make known all the results obtained in every branch of this department of physics. Familiar with every science, and speaking all languages, he hoped, by uniting and tracing to their source the materials scattered through the periodicals of different countries, to furnish geometers the means for the basis for a new and better theory of electricity. The three volumes of his Treatise upon Theoretical and Practical Electricity contain a statement of all the facts observed, with the comment of savans and his own opinion in regard to each one of them. There never was a more impartial compiler nor disinterested parrator. The work shows throughout with what perseverance each individual question was examined, and the care with which they were all subordinated to a general and high order of ideas. “I construct," said he, “ a ladder to the top of which I shall never climb, but, as a conscientious workman, I wish those who shall mount it to find every round of good material, solid, and without defect."

The Bibliothèque Universelle de Genève numbered Auguste De La Rive among its most faithful contributors for nearly half a century. He for a long time directed with indefatigable zeal not only the scientific division considered as his natural domain, but also the literary department, in which he was at first regarded as a usurper. The public acknowledged that, in assuming the control of the periodical, he insured for it an important scientific value, but questioned the wisdom of intrusting the literary part to the direction of a savant, considering that the study of science tends to lessened sensibility to the delicate charm of letters. But never had this portion of the review been as replete with matter of an interesting and entertaining character. Many of the charming productions of Töppfer first saw in it the light of day, and if this amiable artist man. ifested great vigor in his humorous sketches, Auguste De La Rive also showed his good taste in selecting and appreciating the merit of these effusions.

It was not without reflection that Auguste De La Rive partially abandoned his laboratory and favorite studies, to devote a portion of his time, talents, and fortune to the support of a scientific and literary publication which, from the beginning of the century, sustained the moral and intellectual authority of Geneva. He was convinced that the Bibliothèque Universelle exercised, like the Edinburgh Review, a salutary influence. The articles selected gave full information on all the important questions of the day, although regarding them from a national point of view, and thus, while imparting knowledge, kept patriotism alive. His comments upon literature and art, full of elevated sentiment and respect for human understanding, left a very pleasing impression upon the mind of the reader. Nothing was admitted into the journal which could not be read aloud in the parlor, or could cause uneasiness to the mother of a fam. ily. Somewhat of puritanism in ideas, and a certain ansterity in conduct, was not displeasing to De La Rive. He admitted that, if carried to excess, these qualities became ridiculous; but their absence he thought led to disorder. A small country, he said, can exist only under the double condition of having a fixed faith in certain principles, and in conforming the life to them; it must have a physiognomy of its own, and keep it intact; must be itself, and not everybody else; must preserve its own identity, a very diffi

cult matter when railroads tend to mingle all the world into one community-impossible, unless from time to time some voice of authority brings into harmony the discordant elements of society.

In 1815, when Switzerland regained her ancient liberty, Geneva became the temporary abode of many illustrious persons politically distinguished. Some came to enjoy the natural beauty of the shores of Lake Léman, or to rest for a few days in this celebrated city, placed at the confluence of the routes from the north of Europe, from France, and from Italy; others, banished from their native land, sought an asylum among its hospitable inhabitants. Never was there a more singular mingling of the people of every nation, of the representatives of all the continental countries, many of whom had met before on the field of battle, and of England, which had been separated from the rest of Europe for more than thirty years, with the sons of the East, unmistakable in their peculiar type of humanity. In the streets every kind of costume appeared, every language was spoken; in the social assemblies every nationality fraternized.

Meanwhile the Genevese legislators, intrusted with the formation of a constitution for the canton, and anxious to obliterate all traces of the long alliance with the forms of the French administration, found, in the Parliament of England and its controlling aristocracy, the beau-ideal of government. Political party-spirit soon attained as great a degree of intensity in this as in countries of much larger extent. Everybod y was in favor of a constitutional government; but while with some, veritable tories, the principle of anthority was supreme, with others, true whigs, the idea of liberty was uppermost, and, as usual in such cases, neither side was willing to make concessions. Gaspard De La Rive, first syndic of the republic, was at the head of the conservative division, while his son, in common with most of the young men, belonged to the liberal party, prominent among whom was a former member of the French Academy, Simond de Sismondi.

Auguste De La Rive was too ardent in temperament and too truly patriotic in feeling to be indifferent to the political events which later threatened the tranquillity of his country. Still professing liberal principles, as in the days of his youth, he determined to resist the encroachments of a turbulent and oppressive democracy, and became in his turn the leader of a new conservative party.

After the revolution in Geneva, and at the time of the Sonder bund war, he resigned his professorship and retired from public life. Still, when, on the annexation of Savoy to France, some uneasiness was feit by the Helvetic government, he was sent to London, as minister plenipotentiary and envoy extraordinary, to guard the interests of the Con. federation. He was treated by the Queen with the highest distinction, and on his return to his native land received a new mark of confidence; he was made a member of the select assembly for the revision of the

« AnteriorContinuar »