— 137 — 



derivatives of the sesquiterpene by means of bromine or hydrochloric 

 acid gas, and to isolate definite products of oxidation by treating with 

 permanganate failed, the latter experiment only yielding resinous bodies 

 of aromatic odour. The terpene appeared to be sensitive to light 

 to this extent that, after having been kept for 18 months in a stop- 

 pered glass bottle the rotation had fallen to -f-ioi,2°, the other con- 

 stants being almost unchanged. 



Ionone. In the American Journal of Pharmacy, S. P. Sadtler 1 ) 

 discusses the preparation, separation, characteristics, and physical pro- 

 perties of a- and /?- ionone. We cannot altogether agree with the 

 author's opinion that Tiemann's separation of the two isomerides by 

 steam distillation of their bisulphite solutions is very satisfactory, 

 for according to our experience this process gives rather inaccurate 

 values, and in particular do we regard it as unsatisfactory to pronounce 

 an opinion on the /?- ionone contents of an ionone -mixture on the 

 basis of results obtained by this method; for in the first place the 

 ionone which has separated by steam distillation without addition of 

 an alkali from the bisulphite solution of a mixture consisting for the 

 greater part of a-ionone, is not pure /?- ionone. It is of course pre- 

 supposed that the distillation is continued until there is a pronoun- 

 ced foaming, which ultimately prevents its continuance. In the se- 

 cond place, when the bisulphite solution of a mixture consisting chiefly 

 of /J -ionone is distilled and strong foaming ensues, by no means 

 all the /?- ionone has passed over. It is possible after liberating the 

 supposed a-ionone which has remained behind in combination, and 

 after treating it repeatedly with bisulphite and subjecting it to steam 

 distillation, to separate still considerable quantities of /? -ionone. 

 But even in the case of a mixture consisting chiefly of a-ionone it 

 is possible, after treating it three or four times with bisulphite, to prove 

 the presence of small quantities of /?- ionone by subsequent steam 

 distillation without the addition of alkali. Hence the investigator might 

 be tempted to suppose that every time the bisulphite treatment was 

 applied it effected the inversion of certain quantities of a-ionone into 

 /?-ionone. In making this statement we continue of course to pre- 

 suppose that the steam distillation is continued to strong foaming. 

 A further source of the inaccuracy of this method lies in the loss of 

 oil, amounting to about io°/ , which is caused by any bisulphite 

 treatment of small quantities of ionone. In our opinion the method 

 does give a guide for the estimation of the mutual relations of the 

 two isomerides, but we consider it to be too unreliable for the 

 determination of the percentage proportions of a- and /?-ionone. In 

 conclusion, the author, apparently influenced by the Patent law-suits 



a ) Americ. Journ. Pharm. 81 (1909), 181. 



