Out of the fire...
That seems to be the consensus on how the discovery was made. Possibly someone, picking over still-warm ground in bare feet, found the "first" piece with an unwary toe. Or, perhaps, less painful but just as fortuitous -- a sharp eye spotting a gleam on a slope of cooled lava, or an innocuous rock broken to reveal obsidian ... volcanic glass.
Early Methods
However it happened to be found, the "new" material proved useful. Careful knapping of the lumps produced clean, sharp edges, for instance, invaluable for many tasks. The material itself -- cool, slick, shiny -- must have been a source of fascination. That's a safe assumption because, not content to simply find and use the glass, more than three thousand years ago, humans found a method to create it, though not yet to easily shape it as it was being formed. The first true glass may have been made as early as four thousand years ago. Among the methods used to create glass objects were the core forming, casting and cutting methods. Each amounted almost to an art form on its own, and all of those methods produced unique objects that were often as lovely as they were prohibitively expensive.
Breakthrough
True control over the substance, however, was not dreamt of until some Romans, around 50 BC, discovered that the molten substance in their glass crucibles could be gathered on the tip of a hollow pipe, and blown outward like a soap bubble. Unlike the other methods for shaping glass objects, this glassblowing (or glass blowing, or glass-blowing), could be accomplished quickly. It was the ease and speed of this process which transformed glass into a fact of everyday life, rather than the luxury item it had been until then.
Transformation, and Glass in the Present Day
Today, glassblowing is almost, but not truly, a lost art. True mass production techniques have largely replaced the human artists who once sculpted molten glass into beautiful and useful forms that graced households and became heirlooms. It is curious to note, however, that, perhaps because of the slightly elevated element of risk involved in working it, glass was, historically speaking, not often a medium for pure art. Glass objects were almost always functional first and beautiful simply because that was an inherent quality of glass. As production of utilitarian glass objects became less and less like true art, however, there did arise some who began to use glass as a primary medium for art. Perhaps the earliest and most prominent of these was Emile Gallé (1846-1904), who stated:
"My own work consists above all in the execution of personal dreams: to dress crystal in tender and terrible roles, to compose for it the thoughtful faces of pleasure or tragedy...to impose upon it qualities I should like to have in order to incarnate my dream and design.... I have sought to make crystal yield forth all the tender or fierce expression I can summon when guided by a hand that delights in it."
-- Emile Gallé, Ecrits pour L'Art 1884-1889
Emile proved to be about a century ahead of his time: during the 1940's, a number of American artists became interested in using glass as an art medium. It took twenty more years, however, before those artists would begin directly creating glass objects -- until then, skilled glassworkers worked in collaboration with the artists, trying to reproduce their dreams. Still, the idea, once birthed, proved viable, and the American Studio Glass Movement became a reality. Today, glassblowing is a skill and an art taught at many universities throughout the world. They may number much fewer than painters or sculptors, but today, as yesterday before, skilled glassblowers still lift lovingly crafted pieces out of the fire.