...and oxides, I have detected, in some zircons, erbium, didymium, yttria, and another substance, whiuh exists in such small quantity that I have not yet...not seem to have much connection with the subject. In studying the spectra of crystalline blowpipe beads, it seemed desirable to examine those made with...

...be of importance, except as modifying the physical and optical properties, the didymium giving its usual characteristic absorption-bands (zircons from...experiments which at first did not seem to have much connexion with the subject. In studying the spectra of crystalline blowpipe-beads, it seemed desirable...

...optical properties, the didymium giving its usual characteristic absorption-bands (zircons from 8veneroe, Norway), and the manganese the same spectrum as that...experiments, which at first did not seem to have much connexion with the subject. In studying the s,iectra of crystalline blowpipe-beads, it seemed desirable...

...as that of garnets (zircon? from an unknown locality in Siberia*). This method, however, fails to g^ evidence of a new earth ; for since the publication...experiments, which at first did not seem to have much connexion with the subject . In studying the sppctra of crystalline blowpipe-beads, it seemed desirable...

...light, that an almost inappreciable amount is sufficient to produce the spectra to great perfectipn — in fact so small an amount, that the total quantity...experiments, which at first did not seem to have much connexion with (he subject. In studying the spectra of crystalline blowpipe-beads, it seemed desirable...

...spectra, which seemed sufficient to establish its existence, are really duo to compounds of zircouia with the oxides of uranium, which have such a powerful...small an amount, that the total quantity which misled mo was only a few thousandths of a grain ; and its presence might easily have remained unsuspected,...

...oxides of uranium, whii-h have such a powerful action on light that an almost inappreciable amount H sufficient to produce the spectra to great perfection — in fact, so small an amount that the tot d quantity which misled me \vas only a few thousandths of a grain ; «• d its presence might...