The three palimpsests Verona, Biblioteca Capitolare, Veronenses (hereafter: Veron.) XV, XL, and LXII contain rewritten bifolios of late antique copies of works by Gaius, Vergil, Livy, and other classical Latin authors. Because they are very old, and in some cases the only, witnesses of the manuscript tradition of these works, they have attracted the attention of scholars since the beginning of the nineteenth century, when chemical reagents were the only means to make the washed-off letters visible again. Scholars applied a great variety of reagents to them and attested to their use in an unusually open way in private letters and print publications. These three codices are thus ideal objects for a case study on the use of and thoughts on chemical reagents in nineteenth-century palimpsest research. Although this widespread technique did enormous damage to outstanding cultural heritage in many Western European libraries and thus has had a significant impact on the field, it has not yet been widely explored via a historical approach based on written sources.  1 Giuliari 1888, 79 [1993, 79]: '[…] i tre nostri più famosi palinsesti ai N. XV, XL, e LXII [...]' ('[…] our three most famous palimpsests nos. XV, XL and LXII […]'

). For a description of the three manuscripts, see Spagnolo and Marchi 1996, 64-67, 90-92 (with colour plate between pp. 64 and 65), 119-120. On Veron. XV, see recently in great detail Ammirati 2020. On Veron. XL, see also Mommsen 1868, 153-156. 2 On the connection between the Historical School and the discovery of Gaius, see, for instance, Vano 2008. 3 In the appendix at the end of this article, I translate the most important of these sources dealing with the application of reagents or the mixing of tinctures. I cite them using 'source' numbers: S1, S2, etc.