Friedrich Konrad Beilstein (1838-1906), German- Russian encyclopaedist of organic chemistry. Although his own researches were modest, he is remembered for his Handbook of Organic Chemistry (1881), a substantially complete catalogue of organic compounds which has been continued by the German Chemical Society, and is of great value to organic chemists. Beilstein's test for a halogen in an organic compound is quick and useful. An oxidized copper wire is coated with the compound and heated in a gas flame; a blue-green tint to the flame indicates the presence of a halogen. However since some nitrogen compounds also give the colour, the test is only decisive if negative.