created an extraordinary clear type of glass. Struck by its
resemblance to the clearest rock crystals of quartz, Barovier
called it cristallo. This was the birth of modern glass.^7Surprisingly, modern, clear glass would enable several of the key
innovations that empowered the birth of modern science and would define
the birth of the Renaissance. The accidental making of clear glass would
be followed by the (almost) accidental manufacture of mirrored and
curved glass, and the possession of mirrors and small curved lenses would
revolutionize medicine and science in unimaginable ways over the course
of the next century.
Once the Venetians had discovered the technique of making cristallo,
the next major challenge was making a larger flat piece of glass, not an
easy task when you consider that glassmaking always started with a glass-
blown bubble that had to be rapidly flattened while cooling. Additional
experimenting with basic ingredients from faraway lands yielded ever
superior glass, including herbs from Egypt and sand from Mediterranean
trading partners. In an effort to make larger, flat panes of glass, they
adapted a method of blowing glass into cylinders, slicing the molten glass
lengthwise and laying it flat. Early mirrors had been made with a
technique of adding silver flakes on the back of cooling glass, but the
differential coefficient of contraction between the glass and metal made
the glass fracture. The Muranese innovated an amalgam of mercury and
tin, which resulted in less breakage of glass and yielded a shiny and highly
reflective surface.^8 While still a relative luxury good, mirrors became
commonplace enough that they became part of the fabric of everyday life
in the early Renaissance in Venice and Florence. “This was a revelation on
the most intimate of levels: before mirrors came along, the average person
went through life without ever seeing a truly accurate representation of his
or her face, just fragmentary, distorted glances in pools of water or
polished metals.”^9
Therefore, a combination of developments occurred in the mid-1400s
that set the stage for a seismic sociological change. Within a few decades,
Lucretius’s poem “On the Nature of Things” was discovered in a German
monastery, crystal clear glass and advanced mirrors were invented in
Venice, Constantinople fell to the Turks—with the original Greek