On the atomic weight of strontium

Abstract

In the Bakerian Lecture for 1907, “On the Atomic Weight of Radium,” one of us described a rapid and effective method of separating the clear supernatant solution above a precipitate, say of silver chloride or silver bromide, which obviated the necessity of employing any of the ordinary methods of filtration and otherwise greatly simplified the manipulative process. As the contrivance was found convenient in practice and seemed to admit of a high degree of accuracy, we have thought it worth while to make use of it in a redetermination of the atomic weight of strontium which should seek to conform to the standard of precision prescribed by modern procedure in atomic weight estimations. Determinations of the atomic weight of strontium have been made by Stromeyer (1816), Rose (1816), Salvétat (1843), Pelouze (1845), Marignac (1858), Dumas (1859), and Richards (1894-5 and 1905). With the exception of those of Richards these estimations have no claim to great accuracy, and are therefore only of historical interest.