198 Proceedings of the Royal Irish Academy. 



rapidly. The solution, after standing over-night in a stoppered flask, was 

 concentrated, and mixed with alcohol. As the light-yellow amorphous 

 solid thus got showed no tendency to become crystalline, it was converted by 

 treatment with alcoholic potash into diveratrylidene-dicoumaranone. 



(5) Divcratrylidene-Dicoumaranone. 



The tetrabromide (T5 gram) dissolved in 20 c.cs. of semi-normal alcoholic 

 potash, forming a reddish solution, which, when heated for a few minutes on 

 a water-bath, gave a copious separation of a solid. The solid was filtered, 

 washed with water, alcohol, and chloroform, and then recrystallized a couple 

 of times from glacial acetic acid. When dried at 105° C, it softened at 

 279° C, and melted at 285-286° C. As the substance was very sparingly 

 soluble in organic solvents, it was difficult to free it from the small quantity 

 of mineral matter which was present even in the sample analysed : — 



01163 substance gave 0-2915 CO* and 0-0467 H 2 0, 

 corresponding to C 68 - 36, H 4/47, 

 CJSJO, requires C 69-11, H 4-56. 



(The ash left in the boat weighed 0'0014 gram, and if a correction for this 

 is made, the percentages of carbon and hydrogen become 69-19 and 4-52 

 respectively.) 



Divcratrylidene-dieoumaranone crystallizes from glacial acetic acid in thin, 

 yellow, apparently hexagonal plates, which are nearly insoluble in alcohol or 

 toluene, and slightly soluble in chloroform or boiling xylene. 



The crystals dissolve in concentrated sulphuric acid, forming a deep violet 

 solution, the colour of which changes to a light brown after standing for a 

 few hours. 



