his genius for design in the same manner. To these instances may be added that of the late English musical composer, Mr. John Davy, who is said, when only six years old, to have begun the study and practice of his art by imitating the chimes of a neighbouring church with eight horseshoes, which he suspended by strings from the ceiling of a room in such a manner as to form an octave.

But to return to the subject of our notice. Davy first pursued his chymical studies, without teacher or guide, in the manner that has been described, and aided only by the scantiest and rudest apparatus. When still a lad, however, he was fortunate in making the acquaintance of Mr. Gregory Watt, the son of the celebrated James Watt. This gentleman, having come to reside at Penzance for the recovery of his health, lodged with Mrs. Davy, and soon discovered the talent of her son. The scientific knowledge of Mr. Watt gave an accurate direction to the studies of the young chymist, and excited him to a systematic perseverance in his favourite pursuit. Chance attracted to him the notice of Mr. Gilbert (now President of the Royal Society), which the discovery of his merits soon improved into patronage and friendship. The boy, we are told, was leaning on the gate of his father's house when Mr. Gilbert passed, accompanied by some friends, one of whom remarked that there was young Davy, who was so much attached to chymistry. The mention of chymistry immediately fixed Mr. Gilbert's attention; he entered into conversation with the young man, and, speedily becoming convinced of his extraordinary talents and acquirements, offered him the use of his library, and whatever other assistance he might require for the pursuit of his studies. Mr. Gilbert and Mr. Watt soon after this introduced Davy to the celebrated Dr. Beddoes, who had just established at Bristol what he called his Pneumatic Institution, for in

vestigating the medical properties of the different gases. Davy, who was now in his nineteenth year, had for some time been thinking of proceeding to Edinburgh, in order to pursue a regular course of medical education; but Dr. Beddoes, who had been greatly struck by different proofs he had given of his talents, and especially by an essay in which he propounded an original theory of light and heat, having offered him the superintendence of his new institution, he at once closed with that proposal.

The young philosopher was now fairly entered on his proper path, and from this period we may consider him as having escaped from the disadvantages of his early lot. But it was while yet poor and unknown that he had made those acquirements which both obtained for him the notice of his present patrons, and fitted him for the situation in which they placed him. His having attracted the atten tion of Mr. Gilbert, as he stood at his father's gate, may be called a fortunate incident; but it was one that never would have happened, had it not been for the proficiency he had already made in science by his own endeavours. Chance may be said to have offered this opportunity of emerging from obscurity but, had he not previously laboured in the cultivation of his mind as he had done, it would to him have been no opportunity at all.

The experiments conducted by Davy, and under his direction, at the Bristol Institution, were soon rewarded by important results; and of these, Davy, when he had just completed his twenty-first year, published an account, under the title of "Researches, Chymical and Philosophical, chiefly concerning Nitrous Oxyde and its respiration." In this publication, the singularly intoxicating effects produced by the breathing of nitrous oxyde were first announced, and it excited a considerable sensation in the scientific world, and at once made Davy generally known as a most ingenious and philosophic exper

imentalist. He was, in consequence, soon after its appearance, invited to fill the chymical chair of the Royal Institution, then newly established. When

he commenced his lectures here, he was scarcely twenty-two years of age; but never was success in such an attempt more decided and brilliant. He soon saw his lecture-rooms crowded, day after day, by all that was most distinguished in the rank and intellect of the metropolis; and his striking and beautiful elucidations of every subject that came under his review, riveted, often even to breathlessness, the attention of his splendid auditory. The year after his appointment to this situation he was elected also Professor of Chymistry to the Board of Agriculture; and he greatly distinguished himself by the lectures which, for ten successive sessions, he delivered in this character. They were published in 1813, at the request of the Board. In 1803, when only in his twenty-fifth year, Davy was elected a Fellow of the Royal Society, and his contributions to the Transactions, from this time till his death, were frequent, and of the highest value. In 1806 he was chosen to deliver the Bakerian lecture before the Society; and he performed the same task for several successive years. Many of his most brilliant discoveries were announced in these discourses. In 1812 he received the honour of knighthood; and, two days after, he married a lady who brought him a considerable fortune. Next year he was elected a corresponding member of the French Institute. He was created a baronet in 1818. In 1920 he was chosen a foreign associate of the Royal Academy of Sciences at Paris, on the death of the illustrious Watt. He had been for some time Secretary to the Royal Society; and in 1820, on the death of Sir Joseph Banks, he was, by a unanimous vote, raised to the presidency of that learned body; an office which he held till he was obliged to retire, from ill health, in 1827, when his friend and first

patron, the present president, was chosen to succeed him. Little, we may suppose, did either of the two anticipate, when they first met thirty years before, at the gate of Davy's father's house, that they would thus stand successively, and in this order, at the head of the most distinguished scientific association in England.

It is impossible for us, in this place, to attempt anything more than the most general sketch of Sir Humphrey Davy's numerous and most important discoveries in chymical science. Even his earliest publication, the title of which we have already transcribed, was regarded as, for the first time, introducing light and order into an interesting department of the science-the theory of the various combinations of oxygen and nitrogen, the two gases which, mixed together in certain proportions, form our common atmospheric air, but, in other proportions, produce compounds of an altogether dissimilar character. The first memoir by Davy which was read before the Royal Society was presented by him in 1801, before he was a member. It announced a new theory, which is now generally received, of the galvanic influence, or the extraordinary effect produced by two metals in contact with each other, when applied to the muscle even of a dead animal, which the Italian professor, Galvani, had some years before accidentally discovered. It was supposed, both by Galvani and his countryman Volta, who also distinguished himself in the investigation of this curious subject, that the effect in question was an electrical phenomenon, whence galvanism used to be called animal electricity; but Davy showed by many ingenious experiments, that, in order to produce it, the metals, in fact, underwent certain chymical changes. Indeed, he proved that the effect followed when only one metal was employed, provided the requisite chymical change was by any means brought about on it; as, for exam.

ple, by the interposition between two plates of it of a fluid calculated to act upon its surface in a certain manner. In his Bakerian lecture for 1806, he carried the examination of this subject to a much greater length, and astonished the scientific world by the announcement of a multitude of the most extraordinary results from the application of the galvanic energy to the composition and decomposition of various chymical substances. From these experiments he arrived at the conclusion, that the power called chymical affinity was, in truth, identical with that of electricity. Hence the creation of a new science, now commonly called electro-chymistry, being that which regards the supposed action of electricity in the production of chymical changes. The discourse in which these discoveries were unfolded was crowned by the French Institute with their first prize, by a decision which reflects immortal honour upon that illustrious body; who thus forgot not only all feelings of national jealousy, but even the peculiar and extraordinary hostility produced by the war which then raged between the two countries, in their admiration of genius and their zeal for the interests of philosophy.

But the results which this great chymist had already obtained only formed, in his hands, the source of new discoveries. In the interesting and extraordinary nature of its announcements, the Bakerian lecture of 1807 was as splendid a production as that of the former year. There are certain substances, as the reader is aware, known in chymistry by the name of alkalis, of which potash and soda are the principal. These substances chymists had hitherto in vain exhausted their ingenuity, and the resources of their art, in endeavouring to decompose. The only substance possessing alkaline properties, the composition of which had been ascertained, was ammonia, which is a gas, and is therefore called volatile alkali; and this having been found to be a