DAlembert, one of the leading encyclop?dists, like most of them, intensely vain, and about whose origin nothing was known, claimed to be the illegitimate son of the Marquise de Tencin, of scandalous reputation. Mme. de Crquy, in her Souvenirs, scorns the idea, saying also that much of the evil spoken of Mme. de Tencin was untrue; but it is certain that many dark and mysterious rumours clung to the h?tel Tencin, the garden of which extended over what is now the rue de la Paix. Originally intended for the cloister, Mlle. de Tencin refused to take the vows at Grenoble, and was a conspicuous figure in the wild orgies of the Regency. An intimate friend of the notorious John Law, then controller-general of finance, she succeeded, partly by his influence, in getting her brother made Cardinal and Archbishop of Embrun, and during his lifetime did the honours of his h?tel, where, during the days of his power, John Law was a leading spirit. Fortunes were lost and won there in a night, but darker secrets than those of the gambling table were whispered concerning the h?tel Tencin, its inhabitants and guests. More than ordinary scandals, even in the days of the Regent Orlans and his shameless daughters, were circulated, and even the murder of one of her lovers was so far believed that Mme. de Tencin was arrested, though shortly afterwards acquitted.It has been said that the arrest was made at the end of a fte she had been giving at which Robespierre himself was present, and which he had only just left, with professions of the sincerest friendship.I have been deceived! It is impossible that those gentlemen can be descended from the brave C