Versuch zu einer Gruppierung der elementaren Stoffe nach ihrer Analogie in Annalen der Physik und Chemie 15, 1829, pp. 301-307

Dobereiner, J. W.

Published by Johann Ambrosius Barth, Leipzig, 1829

About this Item

FIRST EDITION OF DOBEREINER'S LAW OF TRIADS. In this paper, Johann Wolfgang Dobereiner, a German scientist, was the first to classify elements into groups based on John Dalton's assertions that the atoms of an element have a characteristic mass. In an attempt to classify elements on the basis of Dalton's proposed atomic mass, Dobereiner grouped the elements with similar chemical properties into clusters of three, later termed 'Triads'. The distinctive feature of a triad was the atomic mass of the middle element. When elements were arranged in order of their increasing atomic mass, the atomic mass of the middle element was approximately the arithmetic mean of the other two elements of the triad. For example, "Dobereiner found thatsome groupsofthree elements that havesimilar properties, for examplelithium,sodium andpotassium, theatomic mass(massnumber) for the second elementwas theaverageof thefirstandthird element. For example,lithiumhas amassnumberof7andpotassium has amassnumberof39. Theaverageis (7+39)÷2=23. Themassnumberofsodiumis23. The same was found for some othergroupsofthree elements for examplecarbon(12),nitrogen(14) andoxygen(16)" (GC Science, The Periodic Table). CONDITION & DETAILS: Leipzig: Johann Ambrosius Barth. Ex-libris, only an occasional small stamp within; no exterior marks whatsoever. Octavo (8 x 5 inches; 200 x 125mm). Full volume, 634 pages. 5 fold-out plates and illustrated throughout. Handsomely rebound in half-calf over marbled paper boards. Pristine; tightly and solidly bound. New endpapers. Occasional light age toning. Very good + condition. Seller Inventory # 521

Bibliographic Details

Title: Versuch zu einer Gruppierung der elementaren...

Publisher: Johann Ambrosius Barth, Leipzig

Publication Date: 1829

Edition: 1st Edition.