184 Proceedings of the Royal Irish Academy. 



L ' j ipcroivylidenc-diflava none crystallizes in light yellow prisms, which are 

 sparingly soluble in boiling xylene or chloroform., nearly insoluble in alcohol 

 or ether, and readily soluble in hot pyridine. 



The crystals dissolve in concentrated sulphuric acid to a deep blue 

 solution, the colour of which rapidly changes to purple. 



