Antoine Auguste Lavoisier was born in Paris on the 26th of August 1743. His father was wealthy, and spared no expense on his education. In his twenty-first year he obtained a gold medal from the Academy of Sciences for an essay on the best method of lighting the streets of Paris, but it was some years before he made definite choice of his subject. He published memoirs relating to geology and to mathematics, before the fame of Black’s and Priestley’s discoveries reached him and induced him to turn his attention to scientific chemistry. Lavoisier’s life was divided between his researches and the performance of public duties. In his twenty-fifth year he was elected a Member of the French Academy of Sciences, and, somewhat later, became its treasurer. He drew up numerous reports for the Government on questions on the borderland of Science and Technology; for example, on the preparation of paper for bills, which would not admit of forgery; on experimental agriculture; and on the manufacture of gunpowder. In 1771 he married Marie Anna Pierette Paulze, the daughter of a “fermier-général” or collector of Government revenue; and after his death, she became the wife of Count Rumford, another distinguished scientific man. Made a “fermier-général” himself, it was during his tenure of this office that Lavoisier was accused--along with others holding similar positions--of misappropriating revenue moneys, with the result that, under the dictatorship of the infamous Robespierre, he and twenty-eight of those who held like office were guillotined publicly, on the 8th of May 1794. It is stated that Lavoisier’s last plea, presented by Hallé--for permission to finish a research--was refused by Coffinhal, with the brutal phrase, “La Republique n’a pas besoin de savants; il faut que la justice suive son cours.” Within twenty-four hours the execution took place. Lavoisier was a tall, handsome man, with a remarkably pleasing face. He possessed great influence, and used it all for good. The first account which we possess of Lavoisier’s revolutionary ideas, for revolutionary they were then deemed, was in a sealed note, placed in the hands of the Secretary of the Academy on the 1st of November 1772. It is to the following effect:--