To this same year 1738 belongs a Prize Essay which Voltaire wrote for the Academy of Sciences on the “Nature and Propagation of Fire.” There were plenty of foundries near Cirey, where he could make practical observations on the subject. So he went and observed. Time? The man had on his hands, to be sure, a lawsuit, a tragedy, a history, an enormous correspondence, a “Pucelle,” a love affair, an estate, and a couple of chattering lady visitors who had to be amused in the evenings with music, with readings, and charades. He had nearly finished writing the essay when Madame du Châtelet, whose opinions differed from his and who always had the courage of them, must needs write, in secret, a rival essay on the same subject.

She began to work on it but a month before it had to be sent in. She could only write at night, since Voltaire did not know she was doing it. Her husband—strange confidant!—was the only person in the secret. For eight nights, she only slept one hour in each. Every now and then she thrust her hands into iced water to refresh herself, and paced her room rapidly. The idea possessed her. “I combated almost all Voltaire’s ideas,” she said herself.

He once very happily defined their connection as “an unalterable friendship and a taste for study.” It was friendship and would have been happier for both if no softer feeling had entered it. They were friends who could intellectually differ and be friends still: who never sacrificed truth to sentiment, and whose bond of union was not a passion for each other, but for knowledge.

Both of them sent in their efforts. Madame’s was chiefly remarkable for the statement that different-coloured rays do not give an equal degree of heat: since proved indisputably correct by repeated experiments. Voltaire’s paper, as well as Émilie’s, contained many new ideas. That of itself was sufficient to disqualify their efforts for the prize. It did do so. It was divided between three other competitors, who were correctly orthodox and anti-Newtonian.

Then Madame told her secret, and Voltaire wrote a favourable anonymous review of that essay which contradicted his own, and should have made Madame du Châtelet famous in a better way than as his mistress.

Both of them were as disappointed as two children might have been at their failure. “Our Essays really were the best!” they wrote and told Maupertuis, almost in so many words. They were, although neither of them is now worth much as science. Some of their theories have been superseded; or proved absolutely wrong. But they were wise for their age, and brilliantly expressed. That may be said, but not much more than that, for all Voltaire’s scientific works. They were the alphabet of the language—to teach a scientific childhood to think for itself. It is because they accomplished that aim to the full that they are forgotten to-day.

CHAPTER X
PLEASURE AT CIREY

On December 4, 1738, there arrived at Cirey, having been almost upset out of her post-chaise, and actually compelled to wade through the midwinter mud of the worst roads in France, a visitor, Madame de Graffigny.

Fat and forty was Madame: a vulgar, cheerful, gossiping old nurse, already an ardent hero-worshipper of Voltaire, whom she had met at Lunéville, and with something of literary taste on her own account. The Graffigny had, in fact, caught that eighteenth-century epidemic which showed itself in easy wit, easy writing, and easy morals. She had a brute of a husband from whom she had just obtained a divorce. She had no money. She had any number of friends. Voltaire seems to have liked her because she was poor, good-natured, and adored him. He came to meet his guest in her room when she arrived at two o’clock on that December morning, with a flat candlestick in his hand, and looking for all the world, said the effusive lady, like a monk. Émilie was there, too. Her greetings were only a shade less warm than her lover’s. Madame de Graffigny was left alone: so that she could then and there sit down to her writing-table and for the benefit of a dear confidant, called Panpan, ring up the curtain on one of the most intimate and minute of domestic comedies ever given to the public.

Some years later Madame de Graffigny obtained some contemporary celebrity by her “Letters of a Peruvian.” They are altogether forgotten. But her “Vie Privée de Voltaire et de Madame du Châtelet” will live as long as the fame of that strange pair and the popularity of gossiping memoirs.