Ernst Lenßen

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Ernst Lenßen , also Lenssen, (born February 28, 1837 in Rheydt , † after 1898) was a German chemist.

From 1853 to 1857 Lenßen was the assistant to Carl Remigius Fresenius in his laboratory in Wiesbaden, which was founded in 1848 . He then worked as a chemist in factories in Crefeld and Hanover and, from 1859, in the stock company for printing and finishing in Mönchengladbach . He lived in Rheydt.

Lenßen developed the triad system of the arrangement of chemical elements (an early forerunner of the periodic table ) by Johann Wolfgang Döbereiner . He published on this in 1857 when he was at an agricultural institute in Wiesbaden. He classified the 58 elements known at the time in 20 triads and these triads (groups of three elements) also in 7 supergroups (Enneads). There were three triads in a supergroup, with the mean value of the atomic weights of the middle triad roughly halfway between the mean values ​​of the other two triads. He also makes predictions about previously undiscovered new elements, for example he predicted the atomic weights of erbium and terbium .

In another essay, he also traced the color properties of elements and their oxides back to his theory of triads. For example, according to Lenßen, when barium is burned, a green flame color (blue-yellow) appears, with strontium bluish-red, with calcium yellowish-red, the addition of the colors results in white. Correspondingly, he found laws in other triads that led to colorlessness or white colors. He also mentioned that the triads would explain laws even with specific weights and heat capacity, about which he would publish.

In 1860 he published about the analysis of the water of the brine spring Egestorffshall (Journal for practical chemistry, volume 80, p. 407). He also published papers on analytical chemistry.

literature

  • JC Poggendorff's Biographisch-Literarisches hand dictionary for the history of exact science, Volume 3, Leipzig: Barth 1898, p. 795
  • Eric Scerri: The Periodic Table: Its Story and Its Significance, Oxford UP 2007, pp. 55ff

Individual evidence

  1. ↑ Birth and career data according to Poggendorff in the edition of 1898, at that time still alive as not otherwise recorded in Poggendorff.
  2. ↑ Lenßen, On the grouping of the elements according to their chemical-physical character, Annalen der Chemie und Pharmazie, Volume 103, 1857, pp. 121-131
  3. ↑ Lenßen, Zur Farbenlehre, Annalen der Chemie and Pharmacie, Volume 104, 1857, pp. 177-184
personal data
SURNAME Lenßen, Ernst
ALTERNATIVE NAMES Lenssen, Ernst
BRIEF DESCRIPTION German chemist
DATE OF BIRTH February 28, 1837
PLACE OF BIRTH Rheydt
DATE OF DEATH after 1898