Oscar Loew was a German agricultural chemist

Agricultural chemistry

Agricultural chemistry is the study of both chemistry and biochemistry which are important in agricultural production, the processing of raw products into foods and beverages, and in environmental monitoring and remediation...

, active in Germany, the United States, and Japan in the late 19th and early 20th centuries.

Biography

Loew was born in Marktredwitz

Marktredwitz

Marktredwitz is a municipality in the district of Wunsiedel, in Bavaria, Germany. It is situated 22 km west of Cheb, 50 km east of Bayreuth and 50 km south of Hof/Saale.The town celebrated the Horticultural Show 2006 in cooperation with Cheb....

, Bavaria

Bavaria

Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...

, where his father was a pharmacist. He studied at the University of Munich under the noted chemist Justus von Liebig

Justus von Liebig

Justus von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. As a professor, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the...

. Loew was the assistant in 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,...

 at the City College of New York

City College of New York

The City College of the City University of New York is a senior college of the City University of New York , in New York City. It is also the oldest of the City University's twenty-three institutions of higher learning...

 and participated in four expeditions to the southwestern states of the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in 1882 before returning to Munich

Munich

Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...

, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, where he collaborated with Karl Wilhelm von Nägeli

Karl Wilhelm von Nägeli

Karl Wilhelm von Nägeli was a Swiss botanist. He studied cell division and pollination, but became known as the man who discouraged Gregor Mendel from further work on genetics.-Birth and education:...

. Loew became associate professor at Munich University in 1886. In 1893, he was recruited by the Meiji government of Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 as a foreign advisor, and travelled to Tokyo

Tokyo

, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...

, where he remained to 1898. Loew served as instructor at Tokyo Imperial University between 1893–1907, succeeding Oskar Kellner

Oskar Kellner

Oskar Johann Kellner was a German agricultural scientist .-Biography:...

 as professor of agricultural chemistry

Agricultural chemistry

Agricultural chemistry is the study of both chemistry and biochemistry which are important in agricultural production, the processing of raw products into foods and beverages, and in environmental monitoring and remediation...

. He trained many notable Japanese chemists, including Umetaro Suzuki

Umetaro Suzuki

was a Japanese scientist, born in Shizuoka Prefecture. He was one of the students of famed German Chemist, Emil Fisher. In 1910 he was researching the effects of rice bran in curing patients of beriberi when he discovered an active fraction, which he patented as "aberic acid" . In 1935, this...

. While in Japan, he researched the effects of lime

Lime (mineral)

Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...

 on acidic soils.

On the expiration of his contract in 1898, Loew moved to Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

 where he worked in the United States Department of Agriculture

United States Department of Agriculture

The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...

 to 1900. In Washington, he found it very scattered enzyme catalase and carried out investigations on of calcium and Magnesium influence on plant development. He worked for a short time in Puerto Rico

Puerto Rico

Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

 and settled back in 1910 in Munich, where he was employed as private contractor working with soil bacteriological problems before he accepted the position of professor of chemical plant physiology at the University of Munich in 1913.

Loew was a versatile researcher, and produced in several significant technical papers on organic chemistry

Organic chemistry

Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...

 and enzyme theory. He invented a method to produce formaldehyde

Formaldehyde

Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...

 from methanol

Methanol

Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...

 by oxidation with atmospheric oxygen and the of metallic copper as a catalyst. He proposed the name 'catalase

Catalase

Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...

' for the enzyme that decomposes hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...

 to oxygen and water. His work in this area focused on tobacco

Tobacco

Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...

 leaf extracts.

In 1892 Loew observed that both calcium and magnesium can be toxic to plants when there is an excess of one and a deficiency of the other, thus suggesting there may be an optimal Ca:Mg ratio.[4][5] In 1901, with D.W. May, he did further testing and suggested an ideal Ca:Mg ratio of 5 to 4, though for several species maximum growth was obtained across a wide range of ratios. This work was key to identifying the principle of Cation exchange capacity

Cation exchange capacity

In soil science, cation-exchange capacity is the maximum quantity of total cations, of any class, that a soil is capable of holding, at a given pH value, for exchanging with the soil solution. CEC is used as a measure of fertility, nutrient retention capacity, and the capacity to protect...

, and facilitating William Albrecht

William Albrecht

William A. Albrecht PhD, Chairman of the Department of Soils at the University of Missouri, was the foremost authority on the relation of soil fertility to human health and earned four degrees from the University of Illinois. As emeritus Professor of Soils at the University of Missouri he saw a...

's later work on the Base Cation Saturation Ratio

Base Cation Saturation Ratio

Base-cation saturation ratio is a method of interpreting soil test results that is widely used in sustainable agriculture, supported by the National Sustainable Agriculture Information Service and claimed to be successfully in use on over a million acres of farmland worldwide...

 (BCSR) which is a method of interpreting soil test results that is now widely used in sustainable agriculture.

Loew died in Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 in 1940. His grave is at the municipal cemetery of Lichterfelde West

Lichterfelde West

Lichterfelde West is part of Lichterfelde in the Steglitz-Zehlendorf borough of Berlin. It was developed from 1860 through 1900 by a wealthy businessman Carstenn from Hamburg and is a remarkable example of 19th-century Villenkolonie, a German concept of settlements completely made up of mansion...

in Berlin.

Partial bibliography

• Ein natürliches System der Gift-Wirkungen (1893)
• The Energy of Living Protoplasm (1896)
• The Physiological Role of Mineral Nutrients (1899)
• Curing and Fermentation of Cigar Leaf Tobacco (1899)
• Catalase: A New Enzyme of General Occurrence (1900)
• Physiological Studies on Connecticut Leaf Tobacco (1900)
• The Relation of Lime and Magnesia to Plant Growth (1901)
• L'Énergie Chimique Primaire de la Matière Vivante (1904, par Oscar Loew avec la collaboration de M.-Emm. Pozzi-Escot)
• Studies on Acid Soils of Porto Rico (1913)
• Der Kalkbedarf von Mensch und Tier. Zur chemischen Physiologie des Kalks (1924)
• Das Calcium im Leben der Haustiere, 1939