Comments on the literature of the humin fraction of humus

An extensive and critical review of the literature on the humin fraction of humus has demonstrated two patterns of usage of the term which are in conflict with its generally accepted definition. In the first instance, the word humin was widely used to refer to the alkali-soluble products of the hydrolysis of amino acids and/or sugars. In the second instance, what are apparently incorrect translations of German words such as Huminsubstanzen have caused papers describing the humic materials considered collectively to be indexed under the keyword humin in early volumes of Chemical Abstracts. Consequently, 66 of the 201 papers indexed under the keyword humin in Chemical Abstracts, from volume 1 through volume 77 (1972) do not refer to humin as it is usually defined.