Lavoisier Antoine Laurent - Lavoisier in the year one: the birth of a new science in an age of revolution

I n early autumn of 1793, officials of the French National Convention called on Antoine Lavoisier at his private residence in Paris: 243 boulevard de la Madeleine. A block to the west along this fashionable street, work had been suspended, since 1791, on the church Saint-Marie Madeleine, designed in the style of the Greek Parthenon. From the unfinished classical portico, the view south was open down the rue Royale to the Place de la Rvolution, where the guillotine would soon be installed. Dr. Guillotin, like Lavoisier a member of the Parisian scientific elite, had meant the device to be a humane and civilizing reform of the brutality of axes and ropes; he would be as appalled as anyone to see his idea evolve into one of the most horrifying weapons of terror that the Western world has ever known.

The officials had come, on behalf of the dread Committee of Public Safety, to search and seize Lavoisiers papers; in the end they found nothing suspect but some correspondence in foreign languages (English and Italian) from fellow scientists: Lazzaro Spallanzani, Joseph Priestley, Joseph Black, Benjamin Franklin. Lavoisier asked and was granted permission to apply his personal seal to the seized bundle. Probably he feared that more dangerous documents might otherwise be planted in the package by his enemies, though the report filed on the procedure stated that it is not from distrust that he solicits this precaution, but for the sake of order.

The date, according to the French Revolutionary Calendar, was 24 fructidor of the Year One, though neither Lavoisier nor anyone else knew it. So far as they were all concerned, it was September 10, 1793. The French Revolutionary Calendar, though dated from the establishment of the French Republic on September 22, 1792, was not proclaimed and adopted until October of 1793. Therefore, the Year One existed only in retrospect; no one experienced it directly. And yet it mattered. Before the Year One, Lavoisiers life and career had been tidily woven into the social fabric of the Bourbon monarchy. From this day forward his life and work would be reexamined in the new and dangerous context of revolution and terror.

The French Revolutionary Calendar was intended to detach the authoritarian hand of religion from the measurement of timeand to purge the Julian calendar of mathematical eccentricity. The reformed calendar operated on base ten, dividing each month into three ten-day cycles, and each day into ten periods of one hundred minutes worth one hundred seconds apiece. Lavoisier himself was an advocate of the reformed calendar, and in 1793 he was actively at work on a parallel reform of the system of weights and measures; this decimalized method of measurement proved much more durable than the Revolutionary Calendar and remains standard, as the metric system, today. On 24 fructidor of the Year One, another of Lavoisiers scientific colleagues, Antoine-Franois de Fourcroy, came with the other officials to boulevard de la Madeleine to repossess instruments Lavoisier had been using for the weights and measures projecta bad omen, for Lavoisier had calculated that his participation in this public project would ensure his safe passage through the turbulent times.

If Lavoisier had properly understood the danger that the radical new social context of the as-yet-undeclared Year One presented him, he would perhaps have fled the country. Apparently he failed to perceive the extent of his risk, although in other contexts he understoodbetter than any other scientist of his timethe crucial importance of radical changes in point of view. What Lavoisier called le principe oxygine , whose discovery would ensure his permanent and prominent place in the history of science, had been discovered by others before him: Joseph Priestley, who thought of it as fixed air, and Carl Wilhelm Scheele, who called it fire air. Lavoisiers radical act was to understand and define the not-altogether-new gas as oxygen , thus placing it in an entirely new context from which the whole of modern chemistry would begin to evolve. His was an extraordinary exercise in the power of naming.