In 1761 Diderot produced a play. ‘The Father of the Family’ is, it must be confessed, a sad bore with his lachrymose moralities; but he is exhilarating compared to ‘The Natural Son,’ Diderot’s second play, which was acted in 1771. The universal Denis was no playwright. In 1772 he published the ten volumes of plates which he had laboriously prepared to supplement the text of the Encyclopædia; and in May 1773, when he was sixty years old, he visited Catherine the Great. He had had relations with her for some years. One fine day, in 1765, it had suddenly occurred to him that his dearest Angélique, over whom he had poured such streams of paternal sentiment, would have positively no _dot_. Her fond, improvident father had, of course, never attempted to save anything for her, and, if he knew his own disposition, must have known too he never would save anything. The only thing he had of value in the world, besides his head, was his library. Catherine the Great was a magnificent patron of letters; and Diderot was her especial _protégé_. He would sell his books to her! She delightedly accepted the offer. She gave him for them a sum equal to about seven hundred pounds, and appointed him her librarian at a salary of a thousand livres a year, fifty years’ payment being made in advance. For the first time in his history Diderot found himself rich. When a patron so munificent asked him to visit her, how could he decline? All the Encyclopædists were her warm admirers; she herself used to say modestly that Voltaire had made her the fashion. Denis hated long journeys and loved Paris, but go he must. He left France on May 10, 1773. He stopped at The Hague--where he characteristically admired the beauty of the women, and the turbot--and at last arrived at St. Petersburg. For a monarch who complained that she might have been the head of Medusa--everyone turned to stone when she entered the room--Diderot must have been a singularly refreshing guest. It was one of the most charming traits in his character that he respected persons no more than a child does, or a dog. All etiquette fled before his breezy, impulsive personality. The very clothes he arrived in were so shabby, her Majesty had to present him immediately with a court suit. He was with her every afternoon. He said what he liked, and as much as he liked, which was a very great deal. In the heat and excitement of his arguments he would hammer the Imperial knees black and blue, till the Empress had to put a table in front of her for safety. If he ever did recollect her august position, ‘_Allons!_’ she would cry; ‘between men everything is permissible.’ He evolved the most magnificent, impossible schemes for the government of her empire--which would have upset it in a week if she had tried them, said she. During his stay, his dearest Grimm was also a guest. In March 1774, Denis left; and by the time he reached Paris again, was persuaded that he had enjoyed himself very much indeed.