the senseless, sanguinary fury of the “Friends of the People.” His rectitude, his public services, the purity of his private life, the splendour of his scientific achievements—all were unheeded. As Lagrange said to Delambre: “It required but a moment to strike off this head; a hundred years may not suffice to reproduce such another.” [Illustration: LAVOISIER AND BERTHOLLET in the Laboratory of the Sorbonne, Paris.] Of the men who were associated with Lavoisier in the creation of what was known at the period as the antiphlogistic chemistry, the most eminent was Berthollet. =Claude-Louis Berthollet= was born in Savoy in 1748, and, after a medical education, became physician to the Duke of Orleans. Devoting himself to chemistry, in 1781 he was made a member of the Academy, and he became Government Commissary and Director of the Gobelins, the chief tinctorial establishment of France. Although in the main in agreement with Lavoisier, he never wholly subscribed to the idea that all acids contained oxygen. He discovered the bleaching power of chlorine, prepared potassium chlorate, and investigated prussic acid and fulminating silver. In his _Statique Chimique_, published in 1803, he combated the partial and imperfect views of Bergman and Geoffroy with regard to the operation of chemical affinity, and showed that the direction of a chemical change is modified by the relative proportion of the reacting substances and the physical conditions—temperature, pressure, etc.—under which the change is effected. He was one of the first to draw attention to a class of phenomena known as reversible reactions, and gave a number of instances of their occurrence. Berthollet pushed his conclusions so far that he was led to doubt that chemical combination took place in fixed and definite proportions; and his views gave rise to a memorable controversy between him and Proust, in which the latter eventually triumphed. Berthollet enjoyed a great reputation in his time, and played a considerable part in the political history of his country. It was largely to his zeal, sagacity, and skill in developing her internal resources at a critical period when she was hemmed round by foreign troops and her ports blockaded by British ships, that France was saved from conquest. His life was more than once in jeopardy when France was governed by a Committee of Public Safety; but his honesty, sincerity, and courage even impressed Robespierre, and he escaped the perils of the Great Terror. He was an intimate friend of Napoleon, and accompanied him to Egypt as a member of the Institute. He died at Arcueil in 1822. Davy, who visited him at his country house in 1813, says of him:—