— H3 — 



As the methods for the detection of methyl ester of anthranilic 

 acid, benzyl acetate, and geraniol, in blossom oils have been worked 

 out accurately, and successfully employed by various authors, it is 

 difficult to understand how Mr. Petreano has managed not to find 

 these bodies in his oils. But as he does not say how he has made 

 his experiments, nor what he has actually found in them, it is not 

 worth while to waste another word on this chemical performance 

 and the conclusions drawn from it. 



J. Enklaar 1 ) has extended the hydrogenation method of Sabatier 

 and Senderens (reduction with metallic powders in a current of 

 hydrogen) to aliphatic compounds with several double bonds, such 

 as ocimene, geraniol, linalool, citral, etc. The hydrocarbons yielded the 

 corresponding saturated bodies, the alcohols either the corresponding 

 hydrocarbons, or saturated aliphatic alcohols. In the case of linalool 

 this conversion was accomplished at a temperature of 130 to 140 . 

 Citral yielded in addition to the expected aliphatic, a series of cyclic 

 compounds, amongst which an alcohol resembling the menthol of 

 peppermint oil. According to Enklaar's experiments, copper is more 

 suitable for this method than nickel. With regard to the reaction- 

 mechanism, the author is of opinion that the metal does not combine 

 chemically with the hydrogen, but absorbs it. 



Bibliographical Notes. 



Of Semmler's text-book „Die atherischen Ole, nach ihren 

 Bestandteilen, unter Beriicksichtigung der geschichtlichen 

 Entwickelung" (The essential oils, according to their constituents with* 

 regard to the historical development), to the first numbers of which we 

 have already called attention in our Report of October 1905, p. 86, the 

 final number appeared at the end of June of this year. At the time we 

 gave our opinion on the general part of this work, which has appeared 

 in four stout volumes containing about 2700 pages of text. The special 

 part contains in three volumes the principal sections: methane deriva- 

 tives, hydrated cyclic compounds, and benzene derivatives. In each 

 of these principal chapters are described, in the same sequence, the 

 hydrocarbons, alcohols (phenols), aldehydes, ketones, acids, oxides, the 

 several classes of bodies containing sulphur and nitrogen, — first of 

 all the saturated, and then the unsaturated members of each series. 

 Of each body there are treated in detail, its occurrence, isolation, 

 possible synthesis; physical, physiological (pharmacological as well as 

 odoriferous) and chemical properties, in which latter a distinction is 

 made between chemical changes due to physical and those due to 



*) Chem. Weekblad 4 (1907), 322. Accord, to Chem. Zentralbl. 1907, II. 56. 



