Transylvanian captive, which had been prefaced by Luther, he added an appendix holding up the Turks as in many respects an example to Christians, and presenting, in lieu of the restrictions of Lutheran, Zwinglian and Anabaptist sects, the vision of an invisible spiritual church, universal in its scope. To this ideal he remained faithful. At Strassburg began his intimacy with Caspar Schwenkfeld, a congenial spirit. Here, too, he published, in 1531, his most important work, the _Chronica, Zeitbuch und Geschichtsbibel_, largely a compilation on the basis of the Nuremberg Chronicle (1493), and in its treatment of social and religious questions connected with the Reformation, exhibiting a strong sympathy with heretics, and an unexampled fairness to all kinds of freedom in opinion. It is too much to call him "the first of German historians"; he is a forerunner of Gottfried Arnold, with more vigour and directness of purpose. Driven from Strassburg by the authorities, after a short imprisonment in December 1531, he tried to make a living in 1532 as a soapboiler at Esslingen, removing in 1533 for a better market to Ulm, where (October 28, 1534) he was admitted as a burgess. His _Weltbuch_, a supplement to his _Chronica_, was printed at Tuebingen in 1534; the publication, in the same year, of his _Paradoxa_ at Ulm brought him into trouble with the authorities. An order for his banishment was withdrawn on his promise to submit future works for censure. Not interpreting this as applying to works printed outside Ulm, he published in 1538 at Augsburg his _Guldin Arch_ (with pagan parallels to Christian sentiments) and at Frankfort his _Germaniae chronicon_, with the result that he had to leave Ulm in January 1539. He seems henceforth to have had no settled abode. At Basel he found work as a printer, and here, probably, it was that he died in the winter of 1542-1543. He had published in 1539 his _Kriegbuechlein des Friedens_ (pseudonymous), his _Schrifftliche und ganz gruendliche Auslegung des 64 Psalms_, and his _Das verbuetschierte mit sieben Siegeln verschlossene Buch_ (a biblical index, exhibiting the dissonance of Scripture); in 1541 his _Spruchwoerter_ (a collection of proverbs, several times reprinted with variations); in 1542 a new edition of his _Paradoxa_; and some smaller works. Franck combined the humanist's passion for freedom with the mystic's devotion to the religion of the spirit. His breadth of human sympathy led him to positions which the comparative study of religions has made familiar, but for which his age was unprepared. Luther contemptuously dismissed him as a "devil's mouth." Pastor Frecht of Nuremberg pursued him with bitter zeal. But his courage did not fail him, and in his last year, in a public Latin letter, he exhorted his friend John Campanus to maintain freedom of thought in face of the charge of heresy.