M. Bouvard, whom we had known in London, was now Astronomer-Royal of France, and he invited us to dine with him at the Observatory. The table was surrounded by savants, who complimented me on the "Mechanism of the Heavens." I sat next M. Poisson, who advised me in the strongest manner to write a second volume, so as to complete the account of La Place's works; and he afterwards told Somerville, that there were not twenty men in France who could read my book. M. Arago, who was of the party, said, he had not written to thank me for my book, because he had been reading it, and was busy preparing an account of it for the Journal of the Institute. At this party, I made the acquaintance of the celebrated astronomer, M. Pontecoulant, and soon after, of M. La Croix, to whose works I was indebted for my knowledge of the highest branches of mathematics. M. Prony, and M. Poinsot, came to visit me, the latter, an amiable and gentlemanly person; both gave me a copy of their works. We had a long visit from M. Biot, who seemed really glad to renew our old friendship. He was making experiments on light, though much out of health; but when we dined with him and Madame Biot, he forgot for the time his bad health, and resumed his former gaiety. They made us promise to visit them at their country-house when we returned to England, as it lay on our road. To my infinite regret, La Place had been dead some time; the Marquise was still at Arcueil, and we went to see her. She received us with the greatest warmth, and devoted herself to us the whole time we were in Paris. As soon as she came to town, we went to make a morning visit; it was past five o'clock; we were shown into a beautiful drawing-room, and the man-servant, without knocking at the door, went into the room which was adjacent, and we heard her call out, "J'irai la voir! j'irai la voir!" and when the man-servant came out, he said, "Madame est desolee, mais elle est en chemise." Madame de La Place was exceedingly agreeable, the life of every party, with her cheerful gay manner. She was in great favour with the Royal Family, and was always welcome when she went to visit them in an evening. She received once a week, and her grand-daughter, only nineteen, lovely and graceful, was an ornament to her parties. She was already married to M. de Colbert, whose father fell at Corunna.