— 147 — 



analyses of English oil are available, and that in our opinion it is 

 not even proven that it actually contains no geraniol The author 

 also mentions an experiment with pinene, which he heated under 

 pressure to about 200° in the presence of an organic acid (unspecified) 

 of high m. p. and of an indifferent gas (carbon dioxide). After cooling, 

 the limonene which had been formed was distilled over with steam 

 and the borneol isolated after saponification. This method of preparing 

 borneol and limonene from pinene has long been known, and was 

 the subject of a patent granted to Zeitschel 1 ) in 1907. Anyhow 

 the presence of an indifferent gas in Austerweil's process is new. 



Bibliography. 



The majority of the raw materials from which essential oils are 

 prepared are pharmaceutical drugs which have been known and 

 esteemed for centuries, and the knowledge of which is the domain of 

 pharmacognosy. The progress of the last few decades in our know- 

 ledge of the structure and the general chemical behaviour of the con- 

 stituents of drugs has enriched the science of pharmacognosy by a 

 new branch, pharmaco-chemistry, and the principal achievements made 

 in this region of knowledge have been collected by Oesterle in his 

 Grundriss der Pharmakochemie (Manual of Pharmaco-Chemistry), pub- 

 lished Berlin 1909, by Gebr. Borntrager. This very welcome volume, 

 which embraces the literature of the subject up to about the autumn of 

 1908, contains five principal sections, arranged according to the nature 

 of the active principles of the drugs, viz., alkaloids, odoriferous sub- 

 stances, glucosides, dyes (or rather constituents yielding colouring 

 materials) and tanning materials. These sections contain an exposition 

 of the chemical behaviour of the bodies belonging to each particular 

 division, classified according to the names of the drugs. The author 

 admits that this arrangement is unsatisfactory in many cases, as, for 

 instance, when a drug contains both an alkaloid and essential oil, as 

 does pepper. More than one-half of the 530 pages of the work is 

 occupied by the section dealing with drugs containing odoriferous con- 

 stituents, such as essential oils, vanillin, coumarin, etc. Animal drugs 

 are not considered. The arrangement of details is the same as that 

 of the oils in Otto's book, which we discuss hereafter. First come 

 the oils which contain hydrocarbons as their characteristic constituent 

 and the drugs of which the oil contains the same leading constituent 

 (OL Terebintinae ; Fruct. Phellandrii, etc.) an d m next those of which the 

 oil contains alcohols, [Fruct. Coriandri, FoL Menthae, 01. Rosae, etc.) 

 aldehydes (Cort. Cinnamomi zeyL, etc.), ketones, phenols and phenol- 

 ethers, oxides, cumarin or damascenin. At the end comes Rhizoma 



*) Germ. Pat. 204163, Chem. Zentralbl. 1908, II. 1751. 



