  Rousseau’s stay in England was marked by increasing mental instability and he became wrongly convinced that Hume was at the center of a plot against him. He spent fourteen months in Staffordshire where he worked on his autobiographical work, the Confessions, which also contains evidence of his paranoia in its treatment of figures like Diderot and the German author Friedrich Melchior, Baron von Grimm.  He returned to France in 1767 and then spent much of the rest of his life working on autobiographical texts, completing the Confessions but also composing the Dialogues: Rousseau Judge of Jean-Jacques and The Reveries of the Solitary Walker. He also completed his Considerations on the Government of Poland in this period. In later life he further developed his interest in botany (where his work proved influential in England via his letters on the subject to the Duchess of Portland) and in music, as he met and corresponded with the operatic composer Christoph Gluck.  Rousseau died in 1778. In 1794 the French revolutionaries transferred his remains to the Panthéon in Paris.