252*. Claude Louis Berthollet. Chemist.
[Born at Talloire, in Savoy, 1748. Died at Arcueil, in France, 1822. Aged 74.]
After studying at Turin, went to Paris. There elected a member of the Academy of Sciences, and Professor of Chemistry to the Normal and Polytechnic Schools. During the first wars of the Revolution employed in making gunpowder, and converting iron into steel. With Monge, the geometrician, accompanied the French army to Italy and Egypt in order to direct the removal of the plundered works of art. The friendship of these two philosophers, their calmness in pursuing science amidst danger, their courage and kindness to the soldiers, won for them the admiration of the whole army. Berthollet discovered the bleaching properties of chlorine, and the art of fixing the colour of dyes. Also assisted in the establishment of a new chemical nomenclature. Generous, disinterested, heroic; and his modesty equal to his merit.
[Bust to come.]
253. Antoine Laurent de Jussieu. Botanist.
[Born at Lyons, 1748. Died in Paris, 1836. Aged 88.]
One of a celebrated family of botanists; his uncle Bernard, who died in 1777, having been one of the foremost botanists of his age. His most famous work, founded upon his uncle’s great labours, was “The Varieties of Plants, arranged according to their Natural Order.” His whole scientific life was spent in an endeavour to ascertain the natural relations of plants, and, by the aid of fresh discoveries, to justify and complete the system he upheld.
253*. Pierre Simon Laplace. Astronomer.
[Born at Beaumont, in France, 1749. Died in Paris, 1827. Aged 78.]
A great geometrician and physical astronomer. To him we owe the Theory of Probabilities, and the Nebular Hypothesis. He also prepared the way for the Theory of Tides. He discovered the existence of an invariable plane in the solar system. Invented a thermometer. His great work, Mécanique céleste, introduced to the English by Mrs. Somerville in her “Mechanism of the Heavens,” is so complete that no alterations of importance have been made by subsequent discovery.