From at least the 17th century, the Roman glasses attracted antiquarian interest and they began to be removed from the catacombs, in a largely disorganized and unrecorded fashion; now only a "handful" remain in their original position in the catacomb walls. The first significant publication on them was by Filippo Buonarroti in 1716, "Osservazioni sopra alcuni frammenti di vasi antichi di vetro ornate di figure trovati nei cimiteri di Roma" ("Observations on some fragments of antique glass vases decorated with figures, found in the cemeteries of Rome"), in which he made the extraordinary, almost proto-Romantic assertion that the aesthetic crudity of early Christian art, often remarked by connoisseurs of Roman arts, had served to intensify the piety of the worshipper, an early expression of feeling for primitive art. After other studies, the Italian Jesuit Raffaele Garrucci published the first illustrated survey in 1858, with an expanded second edition in 1864. In the 19th century a number of imitations, copies and downright forgeries of Roman pieces were made, mostly in Murano off Venice, by firms such as Salviati. The first major public exhibition of these seems to have been at the Exposition Universelle of 1878 in Paris, by Italian firms.