Bernhard Tollens

Bernhard Christian Gottfried Tollens ( born July 30, 1841 in Hamburg, † January 31, 1918 in Göttingen ) was a German agricultural chemist, who has been dealing with the chemistry and structure of the sugar molecules.

Journey

Bernhard Tollens, son of a merchant, studied chemistry since 1861 at the University of Göttingen, obtaining his doctorate in 1864 and was then first as pharmacist then as a chemist in Nuremberg, Bonn, Heidelberg and Paris worked. In 1870 he returned to Göttingen and was hired as an assistant at the University led by Friedrich Wöhler chemical laboratory. In the same year he qualified for the chemistry. Tollens 1873 was appointed associate professor and given him the management of the agricultural chemistry laboratory at the University of Göttingen. Here he worked until 1911.

Research services

The guiding principle of scientific Tollens was to uncover basic relationships between agriculture and chemistry. As a field of research he chose the carbs. He developed a special form of ring formulas for sugar, which he derived from the Fischer projection and called Tollens formulas. In the textbooks of organic chemistry this Tollens formulas but were mostly replaced later by the ring formulas by Walter Norman Haworth. The named after him Tollens reagent ( alkaline solution of silver nitrate and ammonia) used for the detection of sugars. See: Tollensprobe! Another Tollens reagent is intended for the detection of pentoses. It contains phloroglucinol and hydrochloric acid and produces a violet precipitate. With the model developed by Tollens reagent naphthoresorcinol to glucuronate can be detected in the urine.

Under the direction of the Tollens Agrikulturchemische Laboratory of the University of Göttingen had an international reputation. Above all, students from the United States of North America could be here to educate Agrikulturchemikern and often went on with a complete agricultural studies. One of them was later known as Agrikulturhistoriker Charles Albert Browne. The German Tollens pupils belongs to the agricultural chemist Theodor Pfeiffer.

Tollens is the author of a successful book on the implementation of simple experiments in agricultural chemistry laboratories. He also wrote a multi- aufgelegtes Manual of carbohydrates. Despite his special research focus in the field of sugar chemistry Tollens has never lost the practical application of its research results for the agricultural practice of the eyes. He lectured widely in agricultural societies. The time he was far ahead of its 1887 not to proceed with the first outspoken recommendation to the sugar factory, the payment for the products supplied by the farmers beet according to the weight, but according to the sugar content.

Writings

• Paul Ehrenberg, Bernhard Baule (Editor): Simple tests for the teaching of chemistry. Compiled for agricultural life - chemical laboratories. Berlin 1878, 2nd edition 1894, 3rd edition 1905, 4th, umgearb. u Securities Value Edition, ibid 1920, 5th ed, ibid, 1927.
• Short Handbook of carbohydrates. Breslau 1888; 2nd edition, ibid 1895, 3rd edition, Leipzig 1914, 4, neubearb. Ed by Horst Elsner, ibid, 1935.