The Jüdisches Athenäum – a Jewish reference book from the early 1850s – reports some new stories, and some slightly different versions of well known stories, about Ernst:
In 1828, Paganini, contrary to his normal reticence, took Ernst into his confidence, and gave him some clues as to how he accomplished his technical feats.
In 1829, Ernst travelled to Paris, and, on the way back, gave concerts in Augsburg, Würzburg and Stuttgart.
In 1831, Ernst travelled to Paris again, where he gave more concerts, and then lived for several years in Switzerland where he lived in retirement, practising his art. He then travelled to Italy [i.e., the modern South of France], but became ill on the journey and returned to Paris, where he received the honour of an invitation to play before the Royal family. On going to Warsaw, where he gave several concerts for the poor, Ernst decided to go to St Petersburg and arranged some concert dates. At this moment, a commissioner of police appeared, and said that any Jew travelling to Russia had to pay a substantial amount of tax, and accordingly demanded the payment. Ernst was deeply aggrieved by this and sent word to St Petersburg reporting what had happened, and saying that nothing could redeem the insult. The Czar, mortified by what had occurred, sent two separate messengers to try and appease Ernst, but he remained implacable and cancelled his Russian tour.
Jüdisches Athenäum: Gallerie berühmter Männer jüdischer Abstammung und jüdischer Glaubens von der letzters Häfte des 18. bis zum Schlu erstes Häfte des 19. Jahrhunderts (Leipsig: Verl.-Comptoirs, 1851), pp.33-7.
Rather than living in Switzerland ‘for several years’ as the passage states, it is more likely that Ernst stayed only from early April to late October 1833 (see HWE:52); the Warsaw incident is likely to have occurred in March 1842 (see HWE:95).