In 1755 he was sent to London as secretary to the French embassy, and was chosen a member of the Royal Society. In 1756 he went to Canada as captain of dragoons and aide-de-camp to the marquis of Montcalm; and having distinguished himself in the war against England, was rewarded with the rank of colonel and the cross of St Louis. He afterwards served in the Seven Years’ War from 1761 to 1763. After the peace, when the French Government conceived the project of colonizing the Falkland Islands, Bougainville undertook the task at his own expense. But the settlement having excited the jealousy of the Spaniards, the French Government gave it up to them, on condition of their indemnifying Bougaiuville. He was then appointed to the command of the frigate “La Boudeuse” and the transport “L’Étoile,” on a voyage of discovery round the world. He set sail from Nantes in November 1766, taking with himCommercon as naturalist, and Verron as astronomer. Having executed his commission of delivering up the Falkland Islands to the Spanish, Bougainville proceeded on his expedition, and touched at Buenos Ayres. Passing through the Straits of Magellan, he anchored at Otaheite, where the English navigator Wallis had touched eight months before. The expedition having crossed the Pacific Ocean, and the men now suffering from scurvy, the ships came to anchor off the Island of Borou, one of the Moluccas, where the governor of the Dutch settlement supplied their wants. It was the beginning of September, and the expedition took advantage of the easterly monsoon, which carried them to Batavia. Thence they proceeded to the Isle of France, where they left Commerçon and Verron. In 1769 the expedition arrived at St Malo, after a voyage of two years and four months, with the loss of only seven out of upwards of 200 men. Bougainville’s account of the voyage (Paris, 1771, 4to) is written with simplicity and with some humour. The art of making astronomical observations at sea was then much less perfect than now, and, consequently, Bougainville’s charts are found to be erroneous, particularly as to the longitudes. After an interval of several years, he again accepted a naval command and saw much active service between 1779 and 1782. In the memorable engagement of April 12, 1782, in which Rodney defeated the Count de Grasse, near Martinique, Bougainville, who commanded the “Auguste,” succeeded in rallying eight ships of his own division, and bringing them safely into St Eustace. After the peace he returned to Paris, and solicited and obtained the place of associate of the Academy. He projected a voyage of discovery towards the north pole, but this did not meet with support from the French Government. Bougainville obtained the rank of vice-admiral in 1791; and in 1792, having escaped almost miraculously from the massacres of Paris, he retired to his estate in Normandy. He was chosen a member of the Institute at its formation; and then returning to Paris succeeded Borda as member of the Board of Longitude. In his old age Napoleon I. made him a senator, count of the empire, and member of the Legion of Honour. He died at Paris, August, 31, 1814. He was married and had three sons, who served in the French army. His éloge, composed by Delambre, appears in the Memoirs of the Institute.