of a cord is that which causes their tension to be equal in whatever direction the cord is strained; we find him, at another period, discovering the art of preserving eggs, so that they might be kept fresh and fit for incubation many years, and breeds of fowls propagated at home or abroad, by the eggs being washed with a varnish of oil, grease, or any other substance that would effectually stop the pores of the shell, and prevent the contents from evaporating. Valuable secrets in the making of glass were also discovered by him; he devised a method of making porcelain, and showed that the requisite materials were to be found in France in greater abundance than in the East; and lastly, he rendered enduring service to science by reducing thermometers to a common standard, which continental nations gratefully commemorate by still calling thermometers by his name. A life passed in mental occupations so multifarious as well as useful, surely entitles Reaumur to be termed a true scholar of perse

verance.

The Honourable Robert Boyle,

by a life of virtue and usefulness, merits the epithet to which his birth by courtesy entitled him. He was the youngest son of the first Earl of Cork, and after being educated at Eton, was sent out to travel on the continent. A residence in Florence at the time of Galileo's death, and the almost universal conversation then caused by the discoveries of that great philosopher, seem to have induced Boyle's first attention to science. On returning to this country he very soon joined a knot of scientific men, who had begun to meet at each other's houses, on a certain day in each week, for enquiry and discussion into what was then called "The New or Experimental Philosophy." These weekly meetings eventually gave rise to the Royal Society of London; but part of the original members of the little club, a few years after its commencement, removed to Oxford, and Boyle, influenced by his attachment to these philosophic friends, in process of time took up his residence in that city.

Their weekly meetings were held in his house; and here he began to prosecute with earnestness his researches into the nature of air. By his experiments and invention, the air-pump was first brought into so useful a form that he may be called its discoverer, though the genius of others has since greatly improved that important instrument. He also demonstrated the necessity of the presence of air for the support of animal life, and of combustion; showing not only that a flame is instantly extinguished beneath an exhausted receiver, but that even a fish could not live under it, though immersed in water. His demonstration of the expansibility of air was still more important. Aristotle, three hundred years before the Christian era, taught that if air were rarefied till it filled ten times its usual space, it would become fire. Boyle succeeded in dilating a portion of the air of the common atmosphere, till it filled nearly fourteen thousand times its natural space.

His other discoveries were numerous, every hour of his existence might be said to be devoted to usefulness; and his wealth and station, so far from disposing him to ease and inertion,

were nobly turned by him into grand aids for the advancement of knowledge. Mr. Craik, the intelligent writer already quoted, thus admirably sums up his life of effort:-" From his boyhood till his death he may be said to have been almost constantly occupied in making philosophical experiments; collecting and ascertaining facts in natural science; inventing or improving instruments for the examination of nature; maintaining a regular correspondence with scientific men in all parts of Europe; receiving the daily visits of great numbers of the learned, both of his own and other countries; perusing and studying not only all the new works that appeared in the large and rapidly widening department of natural history and mathematical and experimental physics, including medicine, anatomy, chemistry, geography, &c., but many others, relating especially to theology and oriental literature; and, lastly, writing so profusely upon all these subjects, that those of his works alone which have been preserved and collected, independently of many others that are lost, fill, in one edition, six large quarto volumes. So vast an amount of

literary performance, from a man who was at the same time so much of a public character, and gave so considerable a portion of his time to the service of others, shows strikingly what may be done by industry, perseverance, and such a method of life as never suffers an hour of the day to run to waste."

The lives of Copernicus, Tycho Brahe, Galileo, and Kepler, among astronomers; of Napier, of Merchiston, the inventor of logarithms; of Dollond and Ramsden, the improvers of optical glasses; of Cavendish, the discoverer of the composition of water; of Linnæus and Cuvier, the greatest naturalists; of Lavoisier, Fourcroy, Black, and, indeed, a host of modern chemists; might be singly and in order adduced as inspiring lessons of perseverance. The young enquirer, if he have caught a spark of zeal from the ardour of the tireless minds we have hastily endeavoured to pourtray, will, if he act worthily, strive to make himself acquainted more fully with the doings of these and other great men, and "gird up the loins of his mind" to follow them in their glorious path of wisdom and beneficence.