226 



Something analogous seems to occur with respect to the odour of 

 dextro-and laevogyratory isomerides. We found that d-and l-limonene, 

 even after rigorous purification, have decidedly different odours; 

 and Werner and Conrad *) separated the dimethyl-ether of trans- 

 hexahydrophtalic acid by means of quinine into its antipodes, and pro- 

 ved that the dextrogyratory compound possesses a comparatively 

 strong odour, while the laevogyratory component is almost odourless. 

 For as-and nms-isomerides, moreover, this fact had already been 

 stated formerly, illustrating therefore the influence of molecular 

 symmetry also in this respect : the cis-hexahydrobenzylamine-carboxylic 

 acids are strongly odoriferous liquids, while the corresponding 

 /raws-derivatives are odourless solid substances/ 2 ) 



Porter and Hirst 3 ) found a strong selective absorption of 

 the dextro- and laevo-gyratory components of some red, orange, 

 and yellow amino-diphenyl-alkyl-carbinols, asymmetric dyes which 

 they prepared from p-amino-benzophenone by the aid of the 

 Grignard-reaction. This fact may probably be of interest for 

 the explanation of the selective colouring of living tissues in 

 microscopy by means of different substances. 



The living organism, according to Pasteur, thus uses the one 

 component of the externally compensated mixture or compound, 

 because its physiological action has been adapted to a special 

 nutriment; and to the same cause must also be attributed the 

 different action on the human body of nicotines, atr opines, and 

 adrenalines, which have another configuration than the natural 

 products. 



These views have become most probable, since Buchner 4 ) proved 

 that from yeast-cells, after grinding and crushing them with sand, 

 a clear juice could be obtained after filtering, from which a special 

 ferment, zymase, could be isolated, which produces fermentation 

 as well as the living cells themselves, and that a second sugar-inverting 

 ferment, invertase, is also present in these cells. As zymase and 



!) A. Werner and H. E. Conrad, Ber. d. d. chem. Ges., 32, 3052, (1899). 



2 ) S. Fraenkel, "Die Arzneimittel-Synthese" , 3e Aufl., Berlin, (1912), p. 128. 



3 ) C. W. Porter and C. T. Hirst, Journ. Amer. Chem. Soc., 41, 

 1264, (1919). 



4) E. Buchner, Ber. d. d. Chem. Ges., 30, 117, 1110, 2668, (1897); 31,209, 

 568, (1898); 33, 3307, 3311, (1900); E. Buchner and R. Rapp, ibid., 31, 1084, 

 1090, (1898); 32, 127, 2086, (1899); 34, 1523, (1901); E. Buchner and A. Spitta, 

 ibid., 35, 1703, (1902); E. Buchner and W. Antoni, Zeits. f. physiol. Chem., 

 44, 206, (1905); 46, 136, (1905); etc. 



