— 124 — 



influence exerted on these constants by conjugated double-Unkings 

 which may possibly be present. Whereas, for example, in the meta- 

 series of the menthadienes, sylvestrene and the closely allied carvestrene 

 show a refractive power corresponding to the theoretical one (45,24) 

 [Wallach 45,22 for sylvestrene x ), Kondakow and Schindelmeiser 

 4 5, 10 for carvestrene 2 )], Harries and Antoni 3 ) observed a considerably 

 higher refraction (45,94) in an m-menthadiene obtained synthetically. 

 The formulae propounded for this body by the two investigators both 

 show a system of conjugated double-linkings. The conditions in the 

 more accurately known menthadienes of the p- series are entirely 

 similar. The limonene and dipentene groups without conjugated 

 double -linking behave optically normally; a p - menthadiene produced 

 by Harries 4 ) from dihydrocarvylamine shows considerably higher 

 refraction, and also contains a conjugated double -linking (d-limonenc 

 MR C 44,76; 44,69 instead of 44,97 calculated; 1-limonene MRp 45,23 

 instead of 45,24 calculated; dipentene MRc 45,04; 44,82 instead 

 of 44,97 calculated; MRp 45,43; 45,03 instead of 45,24; p-men- 

 thadiene from dihydrocarvylamine according to Harries MRp 46,17 

 instead of 45,24). A further example is the p-menthadine (MRp 46,98 

 instead of 45,24) produced by Mahla 5 ) from a nitrosohydroxyamino- 

 menthene; the remaining menthadienes (terpinolene, terpinene, etc.) 

 have not yet been examined with respect to their physical constants 

 with sufficient certainty. Yet it is probable that the two phellandrenes 

 also contain conjugated double-linkings, although Wallach's ob- 

 servations on preparations produced from essential oils, gave a 

 refractive power which was absolutely normal. Anyhow in the case 

 of phellandrene from zl 6 -menthenone-2, Harries and Johnson 6 ) 

 observed distinctly higher values. An explanation of these divergent 

 results is still to be looked for. 



Pharmacologico-physiological notes. 



The opinion prevails that the secondary actions observed in the 

 employment of balsams, must be attributed to adulterations. In con- 

 sequence of this, pharmacologico-chemical examinations have been made 

 with various balsams, and on the strength thereof H. Vieth 7 ), in a 

 paper read before the Versammlung Deutscher Naturforscher und Arzte 



*) Liebig's Annalen 252 (1889), 149. 



2 ) Journ. f. prakt. Chem. II. 68 (1903), 190. 



3 ) Liebig's Annalen 328 (1903), 104, 119. 



4 ) Ibidem, 322. 



5 ) Berl. Berichte 36 (1903), 489. 



6 ) Ibidem 38 (1905), 1832. 



7 ) Verh. d. Ges. Deutsch. Naturforscher und Arzte. Meran,1905. II. Vol. 2 d part, 

 p. 364. Ace. to Chem. Centralbl. 1906, II. 1448; comp. also Weiss, The Balsams, 

 Chemist and Druggist 69 (1906), 839. 



