102 



with water vapours. Apart from a series of new examples of experi- 

 ments, the work gives no fresh information, and we may therefore 

 confine ourselves to a reference to what we said in our last Report 1 ). 



From the pen of Dr. Georg Cohn a monograph on „Die Riech- 

 stoffe" has been published by Fr. Vieweg & Sohn, Brunswick. It 

 gives a review of the chemical individuals which have been isolated 

 up to the present and which are important as bearers of perfumes, 

 of their presence, isolation, production, properties, and tests, and deals 

 with the result of the pharmacological and phy to - physiological re- 

 search. Whereas this book is intended more particularly as an intro- 

 duction in this domain, a treatise byjeancard and Satie "Abrege de 

 la chimie des parfums" (Paris, Gauthier-Villars and Masson &Cie.) 

 serves more as a short hand-book which naturally does not give any 

 new information, but of which the value lies in the suitable arrange- 

 ment of the matter, and in the tabular form of the summary of the 

 most important constants. 



Pharmacologico- physiological Notes. 



A. J. J. Vandevelde 2 ) has, by means of plasmolysis, compared 

 a number of essential oils and odoriferous individuals which frequently 

 occur as important components of the former, for their poisonous cha- 

 racter. This was carried out by ascertaining a numerical value, the so- 

 called critical coefficient, i. e. the number of grams of the substance 

 under examination, which is isotoxic with ioogm. absolute ethyl alcohol 

 in its action on the living cell. The action of the alcohol in its turn 

 was again compared with that of a solution of sodium chloride of a 

 definite degree of concentration, which effects or removes the occur- 

 rence of the plasmolysis in the cell, and was reduced to ioo gm. 

 alcohol. Consequently, the smaller this critical coefficient of a com- 

 pound or of an oil is, the greater will be the toxic effect on the 

 organism. Vandevelde now found that for alcohols this critical 

 coefficient is largest; for aldehydes, phenols, etc. it is decidedly smaller. 

 The bodies examined range themselves, according to the values obtained, 

 in the following series, if the coefficient for absolute ethyl alcohol is 

 taken as I oo : 



i. Thymol 0,04 5. Clove oil 0,21 



2. Menthol 0,18 6. Thyme oil (white) . . 0,36 



3. Cinnamic aldehyde . 0,20 7. Ceylon cinnamon oil . 0,44 



4. Cassia oil .... 0,21 8. Thyme oil (red) . . 0,60 



*) Report April 1904, 102. 



2 ) Bull, de 1' Assoc. Beige des chimistes 17 (1903), 269. 



