Monsieur Le Blanc

Sophie Germain was eighteen, self-taught, and barred from the École Polytechnique when she got hold of its lecture notes and started turning in coursework under a man's name. She signed it Antoine-Auguste Le Blanc, a former student. Lagrange, impressed, asked to meet the author.

He was a woman. He kept mentoring her anyway.

Emboldened, she wrote to Carl Friedrich Gauss as M. Le Blanc, and the two corresponded happily for three years on number theory, Gauss reporting himself charmed by his young French colleague.

Then, in 1806, Napoleon's army marched on Brunswick. Germain, in Paris, became convinced Gauss was about to be cut down by a soldier the way Archimedes had been, mid-proof, and did the only thing a sensible person in her position could think of. She wrote to General Joseph-Marie Pernety, chief of French artillery and a friend of her father's, and asked him to please send someone to protect her pen pal. A French officer duly knocked on Gauss's door. Gauss, baffled, replied that he did not have the honor of knowing any Mlle. Germain.

She wrote to him a few months later and explained.

Gauss replied that his esteemed M. Le Blanc had metamorphosed into a person of the noblest courage. He did not seem to mind.