Fysici
Heinrich Geissler (1815-1879) |
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full Johann Heinrich Wilhelm Geissler. German glassblower for whom
the Geissler (mercury) pump and the Geissler tube are named. Geissler
opened a shop in Bonn in 1854 to make scientific apparatus and devised
his mercury air pump in 1855. Later, using an apparatus of his own
invention, he was able to demonstrate, in collaboration with Julius
Plückers, that water reaches its maximum density at 3.8°
C (later determined to be 3.98°). Among his other inventions were
the vaporimeter and the Geissler tube, in which an electric current
produces light when passed through a rarefied gas. © 1999-2001 Britannica.com Inc. Glowing tubes full of gas proliferated and gained scientific
importance in 1855, when glassblower Heinrich Geissler developed
an improved vacuum pump. It was one of Geissler's tubes that Julius
Plücker used when he first observed cathode rays in 1859. |
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