[ 345 ] 



XLI. Fluorescent Relations of certain solid Hydrocarbons foundin 

 Coal-tar and Petroleum Distillates. By Henry Morton, 

 Ph.D. J President of the Stevens Institute of Technology ^^, 



IN the course of a general research on the fluorescent spectra, 

 I have encountered certain facts in reference to anthracene 

 and one of its associated bodies, and also with regard to a new 

 solid hydrocarbon or mixture of hydrocarbons first observed and 

 separated by me from certain petroleum distillates, which seem 

 to merit a special notice. 



It will, I think, avoid confusion first to discuss the substances 

 first named, and afterwards point out the relations and proper- 

 ties of the second class of bodies. 



Proceeding, then, to the consideration of anthracene, I will 

 describe 



The Materials used. — These consisted of: — 1. Crude anthra- 

 cene from L. C. Marquart, of Bonn. This is a dark olive-green 

 pulverulent mass with fragments of a lighter green scattered in 

 it. 2. Crude anthracene from the works of Page, Kidder, and 

 Fletcher, BulFs Ferry, New Jersey, U.S. This was kindly fur- 

 nished by Mr. J. C. F. Chever, Chemical Superintendent, and 

 was in three forms : {a) fused, as a dark olive-green, hard, crys- 

 talline mass; (b) washed and pressed, much like that from 

 Marquart, but of a lighter colour ; (c) in powder, darker and 

 less free from tarry matter than the foregoing. 3. Chemically 

 pure anthracene, supplied by Mr. Schering, of Berlin, a light 

 yellow-brown crystalline powder. 4. A purer form, obtained 

 by washing the preceding with cold alcohol, or by distilling 

 1, or 2 (a) , or 2 (b) in a current of air, as indicated in the ac- 

 companying cut (fig. 1), and 

 then washing with cold alco- 

 hol. 5. A yet purer form, 

 obtained as above by distil- 

 lation with great care and 

 repeated crystallization from 

 hot alcohol as recommended 

 by Kopp (see Moniteur 

 Scientifique Quesneville, Aug. 

 1872, p. 535). 6th. Abso- 

 lutely chemically pure an- 

 thracene, obtained by expo- 

 sure of the hot solution to sunlight and subsequent recrystal- 

 lization. 



Method of observing the Fluorescent Spectrum. — This is essen- 

 tially that described by Stokes as his first method (see Phil. 

 * Communicated by the Author. 



