“I will write to Madame Du Châtelet in compliance with your wish. To speak to you frankly concerning her journey, it is Voltaire, it is you, it is my friend that I desire to see. I can not say whether I shall travel or not travel. Adieu, dear friend, sublime spirit, first-born of thinking beings. Love me always sincerely, and be persuaded that none can love and esteem you more than I.”
“You will have received a letter from me dated yesterday. This is the second I write to you from Berlin. I refer you to what was in the other. If it must be that Emilie accompany Apollo, I consent. But if I could see you alone, that is what I should prefer. I should be too much dazzled. I could not stand so much splendor all at once. It would overpower me. I should need the veil of Moses to temper the united radiance of your two divinities.”
In return, Voltaire compliments the king very profusely. Speaking of the book of the royal author, the _Anti-Machiavel_, he writes:
“It is a monument for the latest posterity; the only book worthy of a king for these fifteen hundred years.”[33]
Frederick was very desirous of visiting France, whose literature, science, and distinguished men he so greatly admired. Early Monday morning, the 15th of August, the king left Potsdam to visit his sister Wilhelmina, intending then to continue his journey _incognito_ into France, and, if circumstances favored, as far as Paris. The king assumed the name of the Count Dufour. His next younger brother, William, eighteen years of age, accompanied him, also under an assumed name. William was now Crown Prince, to inherit the throne should Frederick leave no children. Six other gentlemen composed the party. They traveled in two coaches, with but few attendants, and avoided all unnecessary display.
Frederick spent three days with his sister at Baireuth. Wilhelmina was disappointed in his appearance. The brotherly affection she looked for was not found. He was cold, stately, disposed to banter her, and his conversation seemed “set on stilts.” Leaving Baireuth, the king continued his journey very rapidly toward Strasbourg. When they reached Kehl, on the eastern banks of the Rhine, they were informed that they could not cross the river without passports. One of the gentlemen drew up the necessary document, which the king signed and sealed with his signet-ring. The curiosity of the landlord had been excited, and he watched his guests from a closet. Seeing what was done, he said to Frederstorf, the king’s valet, “Count Dufour is the King of Prussia, sir; I saw him sign his name.” He was bribed to keep the secret.