Willy Marckwald

Marckwald studied at Berlin's Friedrich-Wilhelms-Universität and received there from the First Chemical Institute in 1886 his Promotierung under A. W. Hofmann with a dissertation on organic chemistry entitled Beitrag zur Kenntniss der Thialdehyde und Thialdine.

Three of his outstanding achievements were: At the Second Chemical Institute under Landolt's direction, Marckwald beginning in 1900 turned increasingly toward theory[15] but also to the inorganic chemistry of radioactive compounds.

From 5 metric tons of uranium ore, in 1902 Marckwald succeeded in isolating 3 milligrams of polonium, which he provisionally (vorläufig) named radio-tellurium.

Upon oxidizing this with nitric acid, evaporating to dryness and warming with a solution of ammonia, a residue weighing about 3 mg. was obtained, which apparently contained practically all of the radio-active material, and possessed "enormous" activity.

[21]In 1911 Marckwald and Alexander Smith Russell published evidence suggesting that the radioactive thorium isotope 230Th and ionium are identical.