Una condanna a morte di dubbia utilità: Sarebbe stato molto grave, per i vetrai muranesi, se il seicentesco ricettario Miotti fosse caduto nelle mani dei Boemi?

In 1754 the State Inquisitors of Venice learned that a worker at Daniele Miotti's factory had fled abroad with a copy of his master's books. Fearing that he would divulge secrets—especially in Bohemia, where there were important glass factories—they ordered his death. Was this extreme action really necessary? Did the Bohemians have something to learn from the recipe books or did they already know everything? We know what secrets Miotti's worker could divulge, because the Miotti recipe book still exists (we also know the Darduin recipe book, which Miotti copied), and we can assume that the German world knew Johannes Kunckel's Ars vitraria experimentalis, the German version of Neri's L'arte vetraria published in 1612. By comparing recipes for the most interesting kinds of glass, in particular how to make red glass (transparent and opaque) and chalcedony glass, we can assess the threat. The aventurine recipe was the most dangerous among those that the Miotti recipe book could transmit, and it would have been serious if it had fallen into the hands of the Bohemians, because Kunckel did not know it.