Jenny Hempel
Encyclopedia
Jenny Hempel (19 February 1882 - 13 February 1975) was a Danish
plant physiology
pioneer. In 1916, she was the first Danish
woman to receive a doctoral degree in a botanical discipline
– and until 1956 the only. She discovered the diurnal fluctuations in cell sap acidity in succulent plants, with are now known to be linked with the CAM photosynthetic pathway
.
apothecary. She studied plant physiology
under professor Wilhelm Johannsen
, together with P. Boysen Jensen. She received the degree of magister
in 1911 for her studies on the effect of ether on plant growth. She then worked with S. P. L. Sørensen
at the Carlsberg Laboratory
. There she studied the pH
of plant sap, in particular the diurnal fluctuations in sap acidity in succulent plants first observed by Benjamin Heyne
. She took her PhD on that topic in 1916 becoming the first Danish
female to do so.
In 1917, she married the Norwegian
librarian Wilhelm Munthe
, with whom she had two sons – one on them being Preben Munthe
. After her marriage she gave up her scientific career.
Her discoveries led directly to broader investigations of the pH
of soils and plants by Christen Raunkiær and his student Carsten Olsen
.
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
plant physiology
Plant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
pioneer. In 1916, she was the first Danish
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
woman to receive a doctoral degree in a botanical discipline
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
– and until 1956 the only. She discovered the diurnal fluctuations in cell sap acidity in succulent plants, with are now known to be linked with the CAM photosynthetic pathway
Crassulacean acid metabolism
Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions. The stomata in the leaves remain shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide...
.
Life
Jenny Hempel was the daughter of a CopenhagenCopenhagen
Copenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...
apothecary. She studied plant physiology
Plant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
under professor Wilhelm Johannsen
Wilhelm Johannsen
Wilhelm Johannsen was a Danish botanist, plant physiologist and geneticist. He was born in Copenhagen. While very young, he was apprenticed to a pharmacist and worked in Denmark and Germany beginning in 1872 until passing his pharmacist's exam in 1879...
, together with P. Boysen Jensen. She received the degree of magister
Magister (degree)
Magister is an academic degree used in various systems of higher education.-Argentina:...
in 1911 for her studies on the effect of ether on plant growth. She then worked with S. P. L. Sørensen
S. P. L. Sørensen
Søren Peder Lauritz Sørensen was a Danish chemist, famous for the introduction of the concept of pH, a scale for measuring acidity and basicity. He was born in Havrebjerg, Denmark....
at the Carlsberg Laboratory
Carlsberg Laboratory
The Carlsberg Laboratory in Copenhagen, Denmark was created in 1875 by J. C. Jacobsen, the founder of the Carlsberg brewery, for the sake of advancing biochemical knowledge, especially relating to brewing. It featured a Department of Chemistry and a Department of Physiology...
. There she studied the pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
of plant sap, in particular the diurnal fluctuations in sap acidity in succulent plants first observed by Benjamin Heyne
Benjamin Heyne
Benjamin Heyne M.D. FLS was a Moravian-Scottish, surgeon, naturalist and botanist.In 1793, Benjamin Heyne joined the service of the British East India Company and in 1796 was assigned as the Madras Presidency Botanist to Samalkot....
. She took her PhD on that topic in 1916 becoming the first Danish
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
female to do so.
In 1917, she married the Norwegian
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
librarian Wilhelm Munthe
Wilhelm Munthe
Abraham Wilhelm Støren Munthe was a Norwegian librarian. He worked at the University Library of Oslo from 1903 to 1953.-Personal life:...
, with whom she had two sons – one on them being Preben Munthe
Preben Munthe
Preben Hempel Munthe is a Norwegian economist.He was born in Aker as a son of librarian Wilhelm Munthe and dr.philos. Jenny Hempel , and younger brother of Gerhard Munthe. He finished his secondary education in 1941, and graduated from the University of Oslo with the cand.oecon. degree in 1946...
. After her marriage she gave up her scientific career.
Her discoveries led directly to broader investigations of the pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
of soils and plants by Christen Raunkiær and his student Carsten Olsen
Carsten Olsen
Carsten Erik Olsen was a Danish plant ecologist and plant physiologist, who pioneered the study of plant nutrition in soils of different pH. He was born in Copenhagen and began studies of botany at the University of Copenhagen in 1910, at first with professor Eugenius Warming, then with professor...
.