On Rare and Scattered Metals

Dmitri Mendeleyev's discovery, in March 1869, of a periodic law which governs the behaviour of absolutely all chemical elements was given a hostile reception by some scientists. Even a chemist of such eminence as Robert Bunsen, one of the creators of spectral analysis, made this caustic remark: "One can draw any number of such generali-zations on the basis of figures printed in stock-exchange bulletins."