80 H. G. SMITH. 



water, colourless crystals were obtained ; these were little soluble 

 in cold water but soluble in alcohol. It is doubtful if this was a 

 nitro-compound. The crystals are microscopic needles, acid to 

 litmus, and melted at 113° C; on powdering the fused material 

 it again melted at the same temperature. This is near the 

 melting point of cumic acid, and if it be that acid, then ordinary 

 oxidation of the side chain had taken place. 



Theoretical. 

 As shown above, the molecular weight of the acid of the ester 

 is near 215. The alcohol present is amyl-alcohol, so that the 

 formula for this ester is C 13 H l7 COOC 5 H n assuming the acid to be 

 monobasic. The only consideration is that of the structure of the 

 acid. Eudesmic acid is unsaturated, taking up bromine to form 

 a dibromide. It is not a member of the series of fatty acids, and 

 its characters remove it from the acrylic series. Probably it 

 belongs to the series of acids homologous with cinnamic acid. 

 The formula for cumyl-angelic acid is C 14 H 18 2 having a molecular 

 weight of 218, this approaches very closely the molecular weight 

 found for eudesmic acid. [An aldehyde resembling] 1 cuminaldehyde 

 is frequently found occurring in Eucalyptus oils, and it may be 

 that this has some connection with eudesmic acid. Perkin 2 describes 

 a series of acids he had formed from cuminaldehyde. The cumyl 

 or cumenylacrylic acid C 12 H 14 2 thus obtained consisted of white 

 needles melting at 157° — 158° C, and giving reactions somewhat 

 resembling those obtained from eudesmic acid. The results show 

 some resemblance between the two acids, but there are many 

 differences between them ; the observed molecular weight might 

 suggest cumyl-angelic acid as the more probable. The cumenyl- 

 angelic acid formed by Perkin melted at 123° C; probably the 

 side chain in eudesmic acid constitutes an isomeric form of angelic 

 acid, this may explain the differences in melting points. When 

 the research on this acid is continued, Perkin's experiments will 

 be repeated. The crystalline acid, obtained by the action of nitric 

 acid, had the characters of cumic acid. If this is eventually 



1 Added 25th July, 1900. 2 Journ. Chem. Soc, xxxi , 388. 



