212 Proceedings of the Royal Irish Academy . 



plates which are easily soluble in alcohol, ether, benzene, or chloroform, 

 and scarcely soluble in water. 



The crystals are coloured reddish-brown on contact with concentrated 

 sulphuric acid, in which they dissolve, forming a reddish-brown solution. 



It has been shown by Harries and Miiller (loc. cit.) that a-benzylidene- 

 methylethylketone forms an oxime, melting at 85°-86° C, a phenylhydrazone, 

 melting at 101° C, and that its solution in glacial acetic acid reacts with 

 bromine, forming a dibromide which melts at 109°-110° C. 



2. Further Action of Bcnzaldehyde on a-Benzylidcne-methylethylketone. 



A mixture of equivalent quantities of benzaldehyde and a-benzylidene- 

 methylethylketone was shaken with a large volume of dilute aqueous alkali 

 for about a fortnight. The oil was extracted with ether, and after evapora- 

 tion of the latter, most of the unchanged a-benzylidene-methylethylketone 

 was distilled in a current of superheated steam. When the residue, left in 

 the flask, was reerystallized from alcohol, it melted at 81°-83° C. 



It was found later that when the reaction was allowed to progress for a 

 much longer time, and the extracted product was then distilled in vacuo, a 

 better yield of the compound melting at 81°-83°C. was obtained. 



A still better yield of the product was got by allowing a mixture of 

 8 grams of a-benzylidene-methylethylketone, and 5*3 grams of benzaldehyde 

 with a solution of 1 gram of sodium hydroxide in 100 c.cs. water, and 100 c.cs. 

 alcohol to stand for several days at the temperature of the laboratory. 



The oil which separated was dissolved in warm alcohol, and when the 

 solution was cooled the substance separated in colourless crystals which 

 melted at 81°-83° C. After drying in a desiccator it gave on analysis the 

 following results : — 



0-2548 substance gave 0-7566 C0 2 and 0-1542 H 2 

 corresponding to C 81-0, H 67 

 C 18 H 18 2 requires C 81-2, H 6-7. 

 The compound crystallizes from alcohol in prisms which are scarcely soluble 

 in cold, and readily in hot, alcohol. It is very soluble in ether, chloroform, 

 or benzene. 



The crystals are coloured orange on contact with concentrated sulphuric 

 acid, in which they dissolve to an orange-yellow solution. 



By an apparently similar method Harries and Miiller (loc. cit.) obtained a 

 compound, the formula of which is CiJIisOj, but which melts at 68 - 5° G. 

 From the analysis, and the properties of the compound, they regard it as a 

 pyrone derivative. Its oxime, which they prepared, melted at 195°-196° C. 

 As the compound prepared by us melted about fourteen degrees higher than 



