Pyrex is a brand name of a type of glass that is constructed of borosilicate. The Corning Glass Company of Corning, New York, developed Pyrex. Chemically, as borosilicate implies, this type of glass is composed of silica and at least five percent (of the total weight of the elements in the glass) of a chemical called boric oxide. The combination and concentrations of these constituents confers great resistance to temperature change and corrosion by harsh chemicals, such as strong acids and alkalis, to whatever vessel is made of the borosilicate glass. This durability has made Pyrex glassware extremely useful in the microbiology laboratory.

The development of Pyrex in 1924 by scientists at the Corning Company satisfied the demand for high quality scientific glassware that had began in the nineteenth century. Then, the glassware in existence was degraded...