— IOI 



its special value from the criticism interspersed in it, and which will 

 be most welcome particularly to those who wish to make themselves 

 acquainted with the historical development and with the relationship 

 between the individual bodies. 



We only wish to refer here to the work published by J. W. Bran del v ) : 

 "The Volatile Oils 1904", as the interesting parts of the contents have 

 already been communicated in these Reports in the most diverse places. 



Physical notes. 



Some time ago Haller 2 ) already pointed to the increase in the 

 rotatory power of active bodies, which is caused by attaching a radical 

 such as particulary benzylidene, by means of a double - linking. In 

 their last work Haller and March 3 ) compare the following partly 

 new bodies and their rotatory powers with each other: benzylidene 

 camphor; hexahydrobenzylidene camphor, colourless crystals of the 

 melting point 49 obtained by condensation of hexahydrobenzalde- 

 hyde with camphor sodium which had been produced from camphor 

 by means of sodium amide in ethereal solution; benzyl camphor; 

 hexahydrobenzyl camphor obtained by reduction of hexahydroben- 

 zylidene amalgam, boiling point 192 at 24 mm. pressure; cenanthyl 

 camphor, produced by the action of heptyl iodide on camphor sodium, 

 a colourless oil of the boiling point 190 at 25 mm. pressure; cenanthyl- 

 idene camphor by brominating cenanthyl camphor and splitting off 

 the hydrobromic acid by means of diethylaniline; boiling point 180 

 to 182 at 20 mm. pressure. 

 Specific rotatory power: 



a) of the unsaturated bodies 

 benzylidene camphor [«] D -f- 42 5° n ', 



hexahydrobenzylidene camphor „ -j- 1 3 1 ° 3 9', 

 cenanthylidene camphor „ — j— 13 6° 40'; 



b) of the saturated bodies 

 benzyl camphor L«] D -[- 144 oo r , 



hexahydrobenzyl camphor „ -f- 55 07', 



cenanthyl camphor „ -J- 51 13'. 



By this comparison, it is clear that the specific rotatory power 

 of the new hydrated bodies is much lower than that of the corre- 

 sponding benzene compounds. The rotation of the saturated alkyl 

 derivatives is lower than that of the unsaturated derivatives from which 



2 ) Pharm. Review 23 (1905), 321, 339 and 376, 24 (1906), 14 and 39. 

 2 ) Compt. rend. 140 (1905), 1626. 

 8 ) Compt. rend. 142 (1906), 316. 



