After the death of Champollion, Lepsius made a systematic study of the French scholar's Grammaire égyptienne, which had been published posthumously in 1836 but had yet to be widely accepted. In that year, Lepsius travelled to Tuscany to meet with Ippolito Rosellini, who had led a joint expedition to Egypt with Champollion in 1828-1829. In a series of letters to Rosellini, Lepsius expanded on Champollion's explanation of the use of alphabetic signs in hieroglyphic writing, emphasizing (contra Champollion) that vowels were not written.