122 Report of Schimmel 8j Co. 1922. 



refraction (blue to ultraviolet) exercise the same influence on the plant development 

 as does weakened mixed light, while red and yellow light causes the same alterations 

 in the plant as continuous darkness. 



The emulsin obtained by aqueous maceration of almonds and precipitation of the 

 extract with alcohol is a mixture of various enzymes containing, in addition to /?rgluco- 

 sidase (emulsin proper), lactase, gentiobiase, invertase, cellobiase, /?-galactosidase, and 

 other ferments. According to M. Bridel and R. Arnold 1 ) it makes no difference in the 

 preparation of emulsin whether ethyl alcohol, methyl alcohol, or acetone is employed. 

 However, by varying the time during which the precipitant is allowed to act on the 

 precipitate, emulsin preparations may be obtained in which some of the enzymes 

 mentioned, e.g., lactase or invertase, are missing. 



Physiological and pharmacological Notes. 



In an elaborate paper entitled, Die Riechstoffe und das Riechen (On aromatics and 

 the sense of smelling), A. Tschirch 2 ) discusses the hitherto-known investigations and 

 theories on the physiology and chemistry of the sence of smelling published by 

 Zwaardemaker, H. Henning, Rupe and Majewski, Marchand, Ruzicka, and others. Basing 

 on these investigations and his own experience, the author endeavours to answer the 

 question: — Which are the conditions which must be complied with in order that a 

 body shows an odour? Tschirch arrives at the following results: — 



1. The phase of the aromatic must show a certain temperature, and it is likewise 

 of importance whether the aromatic is dissolved, and which is the solvent. 



2. The substance must be readily soluble in air. 



3. The distribution-coefficient for the aromatic and air must be favourable for air, 

 hence in case of a mixture of equal quantities of aromatics the odour of such 

 bodies will predominate which are most soluble in air. 



4. The distribution-coefficient for aromatic + air ■< — >■ lipoid plasma of the olfactory 

 cells must be favourable for the latter. 



5. If it is assumed that chemical reactions are set up between the aromatic and 

 the plasma, the former must contain atoms, atom groups, or ions which are 

 able to react with the plasma molecules. 



6. The osmophoric groups which generally are characterized by a strong tendency 

 to react, are osmophoric only conditionally, at any rate only in cases when 

 they are able to react with the colloidal plasm of the olfactory cells. The 

 general chemical structure, more specially the building-up of the aromatic is 

 of minor importance. A system of the shades of odour basing on the con- 

 stitution of the various aromatics can not be established. 



7. The sensation of odour is not caused by the aromatics, but by the very labile 

 compounds formed in the colloidal olfactory cell-plasm (offering enormous 

 surfaces) and mostly decomposing again instantaneously. These are either 

 adsorption compounds — which is less probable — , or reaction-products between 

 the aromatic (highly-ionised on account of its extreme dilution) and the olfactory 

 cell-plasm which offers the aromatic a most extraordinary great surface in form 

 of olfactory hairs, dimples, or conicles. 



*) Journ. de Pharm. et Chim. VII. 23 (1921), 161. — 2 ) Schiveizerische Aputheker-Ztg: 59 (1921), Nos. 17 

 to 20. From a reprint kindly forwarded to us. 



