336 Proceedings of the Royal Irish Acadenvj. 



ether. It consisted of nearly colouiiess plates, which melted at 101-102° C,, 

 and gave on analysis the following results : — 



0-1993 substance gave 0ol53 COj and 0-1058 HjO, 

 corresponding to C 70-5, H 5-9. 

 CjjHioOa requires C 70-6, H 5-9. 



Piperonylidene-methylethyl-ketone is insoluble in water, but dissolves 

 easily in alcohol, ether, or chloroform. It is coloured red on contact with 

 concentrated sulphuric acid, in which it dissolves, forming a red solution. 



2. Anwaldehyde. 



(a) Anisijlidene-methylethyl-ketone, 



CH3O . CeH, . CH : CH . CO . CH, . CH3. 



A mixture of 130 g. of methylethyl-ketone and 150 g. of anisaldehyde 

 with a dilute solution of sodium hydroxide in 500 c.e. of water was shaken 

 for seven days. The oily solid which had formed separated from petroleum 

 ether as colourless crystals, melting at 53"^ C. It gave on analysis the 

 following results : — 



0-1670 substance gave 0-46D8 COj and OHIO H^O, 

 corresponding to C 75-3, H 7-3. 

 CjoHyOj requires C 757, H 7-3. 



Anisylidene-methylethyl-ketone consists of large platy ci-ystals, which are 

 easily soluble in alcohol, ether, benzene, or chloroform, and insoluble in 

 frater. The crystals are coloured reddish-brown on contact with concen- 

 trated sulphuric acid, in wliich they dissoh'e, forming a reddish-brown 

 solution. 



The dibromide of auisylideue-methylethyl-ketoue was prepared by the 

 action of bromine on the ketone in chloroform solution. It separated from 

 petroleum ether as colourless crystals, which melted at 85° C, and gave on 

 analysis the following results: — 



0"2250 g. substance treated with sodium and alcohol by Stepanow's 

 method required 12-75 c.e. N/IO AgNO., for the complete precipi- 

 tation of the bromide, 



corresponding to Br 45-4. 



C!,2Hi402Brj requires Br 45-7. 



