Many researchers have seen in Theophilus, in his Preface to the Treaty on the arts of the nations of his time, proof of Venetian origin of glass production, especially when he spoke of vases and items attributable to jewelry Murano glass. But nothing legitimate to assume, in the absence of a specific attribute, which Theophilus wanted to allude to glass vases, in fact when he refers to vases or cups made ââwith this material, always adds the adjective “glassy”, omitting only if, as in the case ampoules from the long neck, there can be no doubt whatsoever.
Then, if the material is different from that which is the subject of the discussion, he does not fail to specify it. It is deduced that the Italian vases, to which he alludes in the preface, had to be in material such frequent in use at the time, to have no need of any specification. These were the marble and stone in general, in addition to metals, but certainly not the glass, which for its still poor diffusion in the West, was considered semi precious material.
The same goes for jewelry in general, which was made ââessentially with very different materials from glass, such as stone, wood, bone, ceramics, and so very far from the current production of jewelry Murano glass artistic objects.
Also to be ruled out, groped to solve the obscure problem of the origins of glassmaking in Venice, any hypothesis based on geophysical factors which have their weight in this, as in many other industrial arts. We got from importance of natron for the glass of the Egyptian dynastic period, or the sodium ashes of marine plants for Syriac glass, or potassic ashes of ferns and beech and large quantities of firewood drawn from the vast forests of Europe central for the Nordic glass. In fact, Venice was relatively far from the centers of supply of these raw materials.
Some might argue that in the case of small objects such as jewelry Murano glass components this reasoning can not be taken as evidence, but nevertheless also arguments to the contrary can not lead to any solution of the problem.