INDUSTRIAL PEOGEESS DUEING THE YEAE 1875. lxxxvii 



It has an exceedingly rich tint, recalling that of rosaniline, 

 but inclining more to a garnet red. In mass it is a brown 

 powder with a greenish metallic lustre. Upon investigation 

 it proved to be a bromine-derivative of one of the remark- 

 ably fluorescent bodies discovered by Baeyer, and called 

 fluorescein, obtained by the action of phthalic oxide upon 

 resorcin. Its composition proved it to be a phthalein of di- 

 bromresorcin, and this was confirmed by its successful syn- 

 thesis, by the action of bromine on fluorescein. 



Benedikt has prepared phlorein by the action of nitrous 

 acid on .phloroglucin. It is a beautiful dark-green powder 

 with a metallic lustre, dissolving in caustic and carbonated 

 alkalies with an intense violet color. As it was found to 

 contain nitrogen, its allies, brasilein and hsematein (coloring 

 matters from Brazil-wood and logwood respectively), were 

 examined, and found also to contain it, having been hereto- 

 fore overlooked in the analysis. 



Liebermann has investigated the coloring matter known 

 as emodin, which accompanies chrysophanic acid in the root 

 of rhubarb. Distilled with zinc dust it yielded a substance 

 closely resembling anthracene. But on treating it with 

 acetyl oxide, a mono- and a tri- acetyl derivative were ob- 

 tained, and it was shown to be a derivative of methyl-an- 

 thracene, the next higher homologue of anthracene. Fur- 



/ Cj CD 



ther examination proved emodin to be trioxymethyl-anthra- 

 quinone. 



Liebermann and Fischer, on account of the importance of 

 the oxyanthraquinones as coloring matters, have sought to 

 discover a method by which they could be converted the 

 one into the other. From purpurin they prepared purpu- 

 ramide ; and by the action of nitrous acid on this they ob- 

 tained a bioxyanthraquinone which proved to be identical 

 with the purpuroxanthin of Schiitzenberger, obtained in quite 

 a different way. 



Claus has discovered in the alizarin paste of commerce a 

 peculiar substance which dissolves to a blood-red liquid with 

 alkalies. It crystallizes from acetic acid in large dark-brown 

 needles with a bronze lustre. At 305 to 310 C. it sublimes, 

 and condenses in orange needles. On examination it proved 

 to be the dioxyquinone of chrysene, i. e., the alizarin of chry- 

 sene. Hence Claus gives to it the name chrysezarin. 



