On the 6th September 1793, Casanova wrote:
"I will have my Reveries printed at Dresden, and I will be pleased to send you a copy. I laughed a little at your fear that I would take offense because you did not want my manuscript by sending me the ridiculous sum I named to you. This refusal, my dear friend, did not offend me. On the contrary it was useful as an aid in knowing character. Add to this that in making the offer I thought to make you a gift. Fear nothing from the event. Your system of economy will never interfere with either my proceedings or my doctrines; and I am in no need of begging you, for I think that your action followed only your inclination and consequently your greatest pleasure."
On the insistence of Opiz, Casanova continued his correspondence, but he passed over nothing more, neither in exact quotations from Latin authors, nor solecisms, nor lame reasonings. He even reproached him for his poor writing and did not cease joking at the philanthropic and amiable sentiments Opiz loved to parade while at the same time keeping his purse- strings tight. A number of quarreling letters followed, after which the correspondence came to an end. One of Casanova's last letters, that of the 2nd February 1794, concludes: "One day M. de Bragadin said to me: 'Jacques, be careful never to convince a quibbler, for he will become your enemy.' After this wise advice I avoided syllogism, which tended toward conviction. But in spite of this you have become my enemy. . . ."
Among the Casanova manuscripts at Dux was one giving his final comment on his relations with Opiz. Accusing Opiz of bringing about a quarrel, Casanova nevertheless admits that he himself may not be blameless, but lays this to his carelessness. "I have a bad habit," he writes, "of not reading over my letters. If, in re-reading those I wrote to M. Opiz, I had found them bitter, I would have burned them." Probably Casanova struck the root of the matter in his remark, "Perfect accord is the first charm of a reciprocal friendship." The two men were primarily of so different a temperament, that they apparently could not long agree even on subjects on which they were most in accord.
The complete correspondence is of very considerable interest.
In 1786, Casanova published 'Le soliloque d'un penseur', in which he speaks of Saint-Germain and of Cagliostro. On the 23rd December 1792, Zaguri wrote Casanova that Cagliostro was in prison at San Leo. "Twenty years ago, I told Cagliostro not to set his foot in Rome, and if he had followed this advice he would not have died miserably in a Roman prison."
In January 1788, appeared 'Icosameron' a romance in five volumes, dedicated to Count Waldstein, which he describes as "translated from the English." This fanciful romance, which included philosophic and theological discussions, was the original work of Casanova and not a translation. It was criticized in 1789 by a literary journal at Jena. Preserved at Dux were several manuscripts with variants of 'Icosameron' and also an unpublished reply to the criticism.
In 1788 Casanova published the history of his famous flight from The Leads. An article on this book appeared in the German 'Litteratur- Zeitung', 29th June 1789: "As soon as the history was published and while it was exciting much interest among us and among our neighbors, it was seen that other attempts at flight from prisons would make their appearance. The subject in itself is captivating; all prisoners awake our compassion, particularly when they are enclosed in a severe prison and are possibly innocent . . . . The history with which we are concerned has all the appearances of truth; many Venetians have testified to it, and the principal character, M. Casanova, brother of the celebrated painter, actually lives at Dux in Bohemia where the Count Waldstein has established him as guardian of his important library."
In July 1789 there was discovered, among the papers of the Bastille, the letter which Casanova wrote from Augsburg in May 1767 to Prince Charles of Courlande on the subject of fabricating gold.