That part of the Continent which was under French influence, being strictly closed against the English at this time, it is much to the credit of Napoleon, that he immediately assented to a wish expressed by Davy, and seconded by the Imperial Institute, that he might be allowed to visit the extinct volcanoes in Auvergne, and thence proceed to make observations on Vesuvius while in a state of action. He reached Paris, Oct. 27th, 1813. The French philosophers received him with enthusiasm: it is to be regretted that at the time of his departure their feelings were much less cordial. There was a coldness, and pride, or what seemed pride, in his manner, which disgusted a body of men too justly sensible of their own merit to brook slights; especially when, in spite of national jealousy, they had done most cordial and unhesitating justice to the transcendent achievements of the British philosopher. Nor was this the only ground for dissatisfaction. Iodine had been recently discovered in Paris, but its nature was still unknown. Davy obtained a portion, and proceeded to experiment upon it. This was thought by many an unfair interference with the fame and rights of the original investigators. Davy himself felt that some explanation at least was due, in a paper which he transmitted to the Royal Society; and as the passage in question contained what, though perhaps not meant to be such, might easily be construed into an insinuation, that but for him the results communicated in that paper might not have been obtained, it was not likely to conciliate. There is probably much truth in the excuse offered by his biographer, for the superciliousness charged against him upon this and other occasions, that it was merely the cloak of a perpetual and painful timidity.

It is remarkable that, with a highly poetical temperament, he seems to have been senseless to the beauties of art. The wonders of the Louvre ex

tracted no sign of pleasure: he paced the rooms with hurried steps, in apathy, roused only by the sight of an Antinous sculptured in alabaster, "Gracious Heaven!" he then exclaimed, "what a beautiful stalactite."

From Paris, Dec. 29th, he proceeded without visiting Auvergne to Montpellier, Genoa, Florence, Rome, and Naples, which he reached May 8th, 1814. At various places he prosecuted his researches upon iodine; and at Florence, he availed himself of the great burning lens to experiment upon the combustion of the diamond, and other forms of carbon. At Naples and Rome he instituted a minute and laborious inquiry into the colours used in painting by the ancients; the results of which appeared in the Philosophical Transactions for 1815.

The autumn of 1815 is rendered memorable by the discovery of the safety-lamp, one of the most beneficial applications of science to economical purposes yet made, by which hundreds, perhaps thousands, of lives have been preserved. Davy was led to the consideration of this subject by an application from Dr. Gray, now Bishop of Bristol, the Chairman of a Society established in 1813, at Bishop-Wearmouth, to consider and promote the means of preventing accidents by fire in coal-pits. Being then in Scotland, he visited the mines on his return southward, and was supplied with specimens of fire-damp, which on reaching London he proceeded to examine. He soon discovered that the carburetted hydrogen gas, called fire-damp by the miners, would not explode when mixed with less than six, or more than fourteen times its volume of air; and further, that the explosive mixture could not be fired in tubes of small diameters and proportionate lengths. Gradually diminishing their dimensions, he arrived at the conclusion that a tissue of wire, in which the meshes do

not exceed a certain small diameter, which may be considered as the ultimate limit of a series of such tubes, is impervious to the inflamed air; and that a lamp covered with such tissue may be used with perfect safety even in an explosive mixture, which takes fire, and burns within the cage, securely cut off from the power of doing harm. Thus when the atmosphere is so impure that the flame of the lamp itself cannot be maintained, the Davy still supplies light to the miner, and turns his worst enemy into an obedient servant. This invention, the certain source of large profit, he presented with characteristic liberality to the public. The words are preserved, in which when pressed to secure to himself the benefit of it by a patent, he declined to do so, in conformity with the high-minded resolution which he formed

upon acquiring independent wealth, of never making his scientific eminence subservient to gain :-"I have enough for all my views and purposes; more wealth might be troublesome, and distract my attention from those pursuits in which I delight. More wealth could not increase my fame or happiness. It might undoubtedly enable me to put four horses to my carriage, but what would it avail me to have it said, that Sir Humphry drives his carriage and four?" He who used wealth and distinction to such good purpose, may be forgiven the weakness if he estimated them at too high a value.

The coal-owners of the north presented to him a service of plate, in testimony of their gratitude. He underwent, however, considerable vexation from claims to priority of invention, set up by some persons connected with the collieries, whose attention had been turned with very imperfect success to the same end. The controversy has long been settled in his favour, by the decision of the most eminent names in British science, and the general voice of the owners of the Newcastle coal-field: and while the pits are worked, the name of Davy, given by the colliers to the safety-lamp, cannot be forgotten.

In 1818 he again visited Naples, with a view of applying the resources of chemistry to facilitate the unrolling of the papyri found in Herculaneum. These, it is well known, are generally in a state resembling charcoal, often cemented into a solid mass, and the texture so entirely destroyed, that it is hardly possible to separate the layers. Examination of some specimens transmitted to England satisfied him that they had not been subjected to heat, and that, instead of being a true charcoal, they were analogous to peat or to the lignite called Bovey coal. He concluded, therefore, that the rolls were cemented into one mass by a substance produced by fermentation in their

vegetable substance, and hoped to be able so far to destroy this, as to facilitate the detaching one layer from another, without obliterating the writing. With this view he submitted fragments to the operation of chlorine and iodine, with such fair hope of success, that he was encouraged to proceed to Naples; the Government furnishing him with every recommendation, and defraying the expenses of such assistants as he thought it necessary to take out. His success, however, fell short of his hopes; and partly from dis appointment, partly from a belief that unfair obstacles were thrown in his way by interested persons, he abandoned the undertaking at the end of two months, having partially unrolled twenty-three MSS. and examined about one hundred and twenty, which offered no prospect of success. His visit to Naples led, however, to one conclusion of interest to geologists, that the strata which cover Herculaneum are not lava, but a tufa consolidated by moisture, and resembling that at Pompeii except in its hardness.

In October, 1818, Sir Humphry Davy was created a baronet, as a reward for his scientific services. Soon after his return to England in 1820, died Sir Joseph Banks, the venerable President of the Royal Society. Davy succeeded to the chair, which he retained till forced to quit it by ill health, zealous in fulfilling its duties, without relaxing in his private labours. It would have been better had he not ob tained this honour. His scientific pride disgusted some; his aristocratic airs, unpardonable in one so humbly born, excited the ridicule of others. Much of this weakness may be traced to the pernicious effects of early flattery. Had he been content with chemical fame, he would have spared some mortifications and heart-burnings both to himself and others. His demeanour changed immediately after the delivery of his first lecture. On the following day he

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