121 — 



distilled with water vapour, however, the colourless oil decomposed, 

 and yielded a distillate with an acid reaction and a solid resin-like 

 residue. For this reason, the solid body of this oil must be ob- 

 tained by freezing out; after recrystallisation from acetic acid and 

 from alcohol it showed the following constants: formula C 25 H 26 0, 

 melting point 82 ; boiling point 164 to 166 (17 mm. pressure), molec- 

 ular weight calculated 222^ found 232, 228, [a] D in absolute al- 

 cohol -(-30°. Eyken gives it the name "gonostylol". When boiled 

 with formic acid the alcohol was converted into a sesquiterpene C 15 H 24 , 

 gonostylene, of the boiling point 137 to 139 (17 mm.) di 7 o 0,9183, 

 [«]p in absolute alcohol -[-40 , molecular refraction found 66,7 calcul- 

 ated for C 15 H 24 66,15. It is remarkable that guaiol and guaiene have 

 the same rotatory power, but in the reverse direction. With hydro- 

 chloric acid and with bromine respectively only oily products of ad- 

 dition were obtained. When treated with glacial acetic and sulphuric 

 acids according to Bertram-Walbaum, no alcohol was formed; the 

 bulk of the terpene remained unchanged. 



Aldehydes and ketones. 



We have already repeatedly discussed in our Reports the method 

 for the determination of aldehydes and ketones with neutral solution 

 of sodium sulphite, recommended by Sad tier 1 ), and have in every 

 case been compelled to question the accuracy of this method, as an 

 exact titration of the solution containing sodium sulphite is not possible. 

 Further studies of his method have shown Sad tier 2 ) that he was in 

 error with regard to the increase in the application of his method. 

 The author determined again the usefulness of the method for citral, 

 cinnamic aldehyde, benzaldehyde, vanillin, carvone, pulegone, form- 

 aldehyde, citronellal, camphor, menthone and fenchone. Of these 

 compounds, citral, cinnamic aldehyde, carvone, pulegone, and form- 

 aldehyde reacted with 2 molecules sodium sulphite; benzaldehyde and 

 vanillin with 1 molecule sodium sulphite, and the others not at all. 



In almost every case Sad tier now lets the liquid with oil and 

 neutral sulphite stand overnight, in order to be sure that no further 

 alkali is formed. Previous to adding the sulphite solution, the oils 

 are neutralised with Y 10 th normal alkali solution. Sad tier has recently 

 stated that the disappearance of the characteristic odour (especially 

 in citral, cinnamic aldehyde, carvone, pulegone, and benzaldehyde) is 

 an important sign of the end of the reaction. 



2 ) Report April 1904, 48; October 1904, 119; April 1905, 103; October 

 1905, 30. 



2 ) According to reprint from the Journ. Americ. Chem. Soc. 27 (1905), 1321. 



