The 7x9 foot portrait of Lavoisier (age 45) and his wife Marie Anne Pierrette Paulze (age 30), painted by Jacques Louis David in 1788, is in the collection of the Metropolitan Museum of Art. It shows Lavoisier at work on his epochal "Traité élementaire de Chimie" or

It is easy to trace the subsequent development of chemistry to this work, and it is the cornerstone of what is termed the "Chemical Revolution."

Lavoisier had married the daughter of his business partner when she was only 13 years old, and he was 28. She became an imporant partner in his research. Lavoisier's student Fourcroy said of her that she "knows how to unite the culture of letters with that of the arts and sciences." In addition to keeping lab records and serving as Lavoisier's publicist, she translated scientific papers from English, which he did not read, and studied drawing with David so she could create etchings of his scientific apparatus. The portfolio on the chair in the left background of David's portrait presumably contains the originals of her 13 plates for the "Traité". (She also painted a portrait of Benjamin Franklin as he discussed the American Revolution with Lavoisier and the French economist Pierre Samuel Du Pont, a close friend of the Lavoisiers.)

The detail from her Plate V shows three pieces of apparatus included in David's portrait, the eudiometer for collecting, measuring, and exploding gases over mercury (Fig. 7), the bell jar for collecting gases over water (Fig. 9A), and, at Lavoisier's foot, the 18-pint flask with vacuum-tight copper fittings and a stopcock (Fig.10A) for measuring the density of a gas. [Try to figure out how the apparatus in Fig. 10 should be used for this purpose. Note that between A and B are two stopcocks (Fig. 11) and a connector (Fig. 12). ] [click here for answer]

The Lavoisiers were very well-to-do. He had inherited nearly $2 million (*) at the age of 11, and by 1788 their income was nearly $1 million per year. They paid David 7,000 pounds (nearly $300,000) to paint this portrait. They could afford "Big Science", like the 33-inch burning glass that Scheele suggested using to generate oxygen. Unfortunately much of their income came from Lavoisier's partnership in France's private tax collection agency (the Ferme Général).

Lavoisier was much more than a scientist. He practiced chemistry from 6 to 9 AM and 7 to 10 PM, and all day Saturday. In 1788, besides sitting for his David portrait and completing the "Traité", Lavoisier, as an expert on finance and administration, drafted a memoir for Necker, the Finance Minister, on convoking the States General. On May 5, 1789, this body began meeting as France's first representative assembly in 175 years. When Louis XVI found that they wanted to discuss more than raising taxes, he cracked down, and by June 17 this National Assembly, shut out of their accustomed meeting room at Versailles, took the "Tennis Court Oath" not to disband without a constitution. This meeting, which included 200 lawyers, was recorded by David, a man of strong revolutionary sympathies.

Lavoisier favored reform and served the state well, introducing scientific agriculture, setting the stage for introduction of the metric system, and, most importantly, taking charge of research and manufacture of French gunpowder, which he converted from the worst in Europe to the best.

What became of the others? Within a year and a half the Terror had run its course, the Académie des Sciences had been reconstituted as the Institut de France, Mme. Lavoisier had begun to recover her husband's property and scientific equipment, and there was a public ceremony honoring Lavoisier's memory. Lavoisier's wealthy widow refused persistent proposals from Pierre Samuel Du Pont, with whom she had been intimate in the 1780s, while Lavoisier was deeply involved in scientific farming. In 1800 Du Pont decamped to America, where his son Eleuthère Irénée, a protegé of Lavoisier, set up a gunpowder factory in Wilmington, Delaware. Eleuthère wanted to name his enterprise "Lavoisier Mills" but his father persuaded him to name it "Du Pont de Nemours and Company". When the war of 1812 came, the United States could charge Eli Whitney's mass-produced rifles from Hamden with Lavoisier's scientific gunpowder from Wilmington. In 1805 Mme. Lavoisier married the expatriot American scientist-adventurer Benjamin Thomson (Count Rumford), whom J. M. Thomas has called "a former soldier and statesman...ruthless and arrogant, callously cunning and devious, an unprincipled spy and a calculating womaniser; but...also a philanthropist, a brilliantly effective social reformer, an ingenious inventor and an exceptionally innovative scientist." The marriage ended unhappily in 1809 with Thompson reporting, "After that she goes and pours boiling water on some of my beautiful flowers." She survived until 1836, by which time Germany was beginning to overtake France in the chemical sciences. Nimble David, who had signed 300 guillotine orders during the Reign of Terror in 1794 (when he painted this self portrait) became the official painter to Napoleon.