326 Proceedings of the Royal Irish Academy. 



On acidifying the aqueous alkaline layer an oil was liberated. This was 

 dissolved in warm alcohol, from which it separated as eolouiless prisms, ' 

 melting at 171° C. with effervescence. It was ahnost insoluble in water or 

 petroleum ether, dissolved in benzene or ether, and was readily soluble in 

 hot alcohol. 



4. A nisylidene- hutyl-acetone. 

 CHsO . CeH, . CH : CH . CO . CH, . CJIg. 



By evaporating the ethereal extract from the last experiment an oil was 

 obtained. It separated from warm alcohol as colourless prisms, which 

 melted at 60-61° C, dissolved in methyl alcohol or acetic ester, and was 

 very readily soluble in ether, chloroform, alcohol, benzene, or acetone. On 

 analysis it gave the following results : — 



0-1293 substance gave 0-3670 COg and 0-1019 H2O, 



corresponding- to C 77-4:1 H 8-75. 

 C15H20O.2 requires C 77-58 K 8-62. 



5. Benzylidene-iutyl-acetoacetic Acid. 

 CgHsCH : CH . GO . C 11 (C Jig) . COOH. 



A mixture of 7 grams of benzaldehyde and 12 grams of butyl-acetoaeetic 

 ester was shaken for several days with 200 c.c. of water, to which 12 per 

 cent, caustic soda solution (20 c.c. in all) was added from time to time in 

 quantities of 5 c.c. The oil which separated was extracted with ether, and 

 the ether solution was reserved for the isolation of the ketone. (See below.) 



A white solid was precipitated on acidifying the aqueous layer with 

 dilute acid. It crystallised from alcohol as colourless prisms, which melted 

 with efifervescence at 158-159"^ C. It dissolved readily in alcohol, chloroform, 

 acetic ester, or acetone, less easily in ether or benzene, and was nearly 

 insoluble in petroleum ether. It gave on analysis the following results : — 



0-1200 substance gave 0-3216 CO2 and 0-0802 HgO, 



corresponding to C 7309 H 7-59. 

 CijHjgOs requires C 73-17 II 7-32. 



6. Benzylidene-butyl-acetmu. 



CgHg . CH : CH . CO . CHj . C.Hg. 



On evaporating the ether solution referred to above, an oily, semi-solid 

 residue was left. When this was distilled in a current of steam, benzaldehyle 

 came over first and finally ; when the aldehyde had been distilled, the ketone 



