Kœnig had formerly instructed madame du Châtelet in the philosophy of Leibnitz. Voltaire consequently knew and esteemed him, and was indignant at the persecution he suffered; he took his part openly, and was only restrained from crushing his adversary by Frederic's personal request not to make a jest of his academy or its president. The seeds of animosity, however, between him and Maupertuis, long sown, sprung up and flourished with vigour. Maupertuis contrived to excite a disreputable person of the name of La Beaumelle to attack the poet. His calumnies ought to have met with contempt only; but Voltaire was irritated, and his dislike to Maupertuis increased. The president published a book full of philosophical follies, which Voltaire satirised unsparingly. He wrote a diatribe called "Akakia," and read it to the king; Maupertuis was the butt of a thousand witticisms, and the royal suppers rang with laughter at his expense. But Voltaire was not content to make a jest of Maupertuis only in the royal presence, and Frederic, beginning to think that to attack his president was to attack his academy and also himself, published two pamphlets against Kœnig, which also inculpated Voltaire. The poet was indignant. "I see," he writes to his niece, "that the orange is squeezed; I must now try to save the rind. I am going to write a small dictionary for the use of kings, in which it will be shown that _my friend, means my slave; my dear friend, you are becoming indifferent to me; I will make you happy, I will endure while I need you; sup with me this evening, you shall be my butt to-night._ Seriously, my heart is wounded. Speak to a man with tenderness, and write pamphlets against him--and what pamphlets! Tear a man from his country by the most solemn promises, and treat him with the blackest malignity. What a contrast!" Voltaire was not a man to suffer these attacks without punishing them with a visitation of his unbridled wit. Fearful of attacking Frederic, he revenged himself on Maupertuis, and published "Akakia."