fine-quality glass with improved resistance to heat and shock, suited for chemical ware. It was developed for thermometers and measuring vessels, optical ware, and scientific and industrial uses.

Jena glass was first produced by the German glass chemist Friedrich Otto Schott, who, with Ernst Abbe (Abbe, Ernst) and Carl Zeiss (Zeiss, Carl), founded a glassworks in Jena, Ger., in 1884. The early Jena glass—a sodium–magnesium–aluminum–zinc borosilicate containing some boron trioxide in place of part of the silica of older glasses—foreshadowed later borosilicates, which include Pyrex.