Hermann Sprengel FRS (29 August 1834 – 14 January 1906) was a German-British

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

who discovered the explosive nature of

picric acid Picric acid is an organic compound with the formula (O2N)3C6H2OH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name "picric" comes from (''pikros''), meaning "bitter", due to its bitter taste. It is one of the most acidic phenols. Like ot ...

in 1873, patented safety explosives and invented the mercurial air pump.

Life

He was born at Schillerslage, near

Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...

, on 29 August 1834. Sprengel was the son of George Sprengel. He was educated in

Göttingen Göttingen (, ; ; ) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. According to the 2022 German census, t ...

and earned his degree at the university at

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

in 1858. He moved to England the following year and became a naturalised British subject. He was first employed as an assistant in chemical laboratory in Oxford and then moved to London to work at Guy's and St Bartholomew's Hospitals, before working in the chemical works of Thomas Farmer of Kennington (1865-1870). There he invented a generic class of materials called Sprengel explosives. In addition he invented a very robust and continuously operable device called the

Sprengel Pump The Sprengel pump is a vacuum pump that uses drops of mercury falling through a small-bore capillary tube to trap air from the system to be evacuated. It was invented by Hanover-born chemist Hermann Sprengel in 1865 while he was working in Lo ...

which could reduce the amount of air in a chamber to one-millionth of its volume paving the way for the filament light bulb. He was elected a

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the Fellows of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...

in 1878. His candidature citation read "Distinguished as a Chemist and Physicist. Author of the following researches. *(1) Ueber einen neuen Lothrohrapparat (Pogg Ann v 112 1861) *(2) On the detection of Nitric Acid (J Ch Soc 1865) *(3) Researches on the vacuum (J Ch Soc 1865) *(4) On determining the weight of heterogeneous liquids (J Ch Soc 1866) *(5) Improvements in the preparation of Explosive compounds *(6) The water air-pump (Phil Mag, 1873) *(7) An Air-bath of constant temperature between 100 degrees & 200 degrees C (J Ch Soc 1873) *(8) A method of determining the Specific Gravity of liquids with ease & great exactness (J Ch Soc 1873 & Pogg Ann 1874) *(9) A new class of explosives which are non-explosive during their manufacture storage & transport (J Ch Soc 1873) *(10) Use of water "atomiser" in production of Sulphuric Acid (Ch News 1875)." He died at 54 Denbigh Street, London, S.W., on 14 January 1906, and was buried in

Brompton Cemetery Brompton Cemetery (originally the West of London and Westminster Cemetery) is since 1852 the first (and only) London cemetery to be Crown Estate, Crown property, managed by The Royal Parks, in West Brompton in the Royal Borough of Kensington a ...

. He had never married.

Life

References

Further reading