The Fluorescence and Absorption of Anthracene

A NTHRACENE, because of its intense blue-violet fluorescence, •-^~~*-offers a promising opportunity for the comparative study of the fluorescence of a substance in its different forms: solid, liquid, and solution.The present study was undertaken, in order to make such a comparison, at the suggestion of Professors Nichols and Merritt, of whose inspiring interest the author wishes to express her grateful appreciation.Owing to the impurity of the anthracene used, the work naturally fell into three divisions : (1) the study of the fluorescence of impure anthracene; (2) the purification of the anthracene; (3) the study of the fluorescence of pure anthracene. NATURE OF ANTHRACENE.Anthracene is a benzene derivative, prepared from those portions of coal tar which boil between 340 0 and 360 0 C.In its pure form the anthracene crystallizes in monoclinic plates, and has a blueviolet fluorescence.It melts at 213 0 C. and boils at 351° C. The crude anthracene contains an impurity of unknown composition, chrysogen, the slightest trace of which has been supposed entirely to destroy the blue-violet fluorescence. HISTORY.No study of the fluorescence of the crude anthracene has, so far as the writer is aware, yet been undertaken.The study of the fluorescence of the pure anthracene has been chiefly confined to the solutions.In this field, the work of two men needs to be mentioned, J. Hartley, in England, and O. Knoblauch, in Germany.Hartley 1 studied the absorption bands of solutions of pure anthracene in glacial acetic acid diluted with absolute alcohol.The solutions varied in concentration from 1 part of anthracene in 1,000 of the