Febbuaky 9, 1906.] 



SCIENCE. 



227 



On the whole the book may be pronounced 

 excellent — one that every broad-minded busi- 

 ness man should have, and that deserves the 

 wide acceptance in the colleges that it is find- 

 ing. 



To be adopted as a text-book on economic 

 geology by such an authority on that par- 

 ticular subject as Professor Geo. P. Merrill is 

 enough to show that it is indeed a good one. 

 A. C. Lane. 



Die Riechstoffe. By Dr. Gborg Cohn. 



Braunschweig, F. Vieweg und Sohn. 1904. 



Pp. 219. 



This is Section II., Group 2, Vol. VI., of 

 Bolley-Engler's well-known ' Handbuch der 

 chemischen Technologie,' which is now pub- 

 lished in this separate form for the con- 

 venience of those interested in the study of 

 the perfiunes. 



The book is divided into the following 

 chapters: I., Definition of a Perfume; II., 

 Literature; III., History of Perfumes; IV., 

 Occurrence of Perfumes in Nature ; V., Prepa- 

 ration of Perfumes; VI., Physical Properties 

 of Perfumes; VII., Chemical Behavior of 

 Perfumes; VUL, Quantitative Estimation of 

 Perfumes; IX., Physiological Action of Per- 

 fumes; X., Use of Perfumes; Addenda, and 

 Index. 



Certain branches of organic chemistry have 

 developed so rapidly during the past few years 

 as to have risen almost to the rank of separate 

 sciences. The chemistry of the dyestuffs and 

 of the synthetic drugs, are cases in point. ' 

 While the chemistry of the perfumes has not 

 experienced so great a development as these, 

 it has, nevertheless, reached the point where 

 special books on the subject are necessary, and 

 many have already been published. The his- 

 tory of perfumery goes back to remotest an- 

 tiquity, but that of the chemistry of the per- 

 fumes is comparatively recent. 



The book under review gives a concise sum- 

 mary of our present knowledge of the subject, 

 including the chemical, physical and physio- 

 logical properties of the various perfumes, 

 together with their methods of preparation. 

 The synthetical preparation of perfume sub-^ 

 stances, and the methods of obtaii-jjijig pftr-,,, 



fumes from natural sources, particularly, are 

 treated very fully. 



All plants which yield ethereal oils are 

 classified according to their natural families; 

 and this list is supplemented by an alphabet- 

 ical tabulation of all known ethereal oils, 

 giving their physical constants and chemical 

 constituents. The composition of various 

 artificial ethereal oils, at least so far as ascer- 

 tainable from the patent literature, is given 

 in a later chapter (X.). 



In the special part (included in chapter V.), 

 108 pages are devoted to a detailed discussion 

 of the various perfume substances. The classi- 

 fication is based upon chemical structure, and 

 includes the following groups: Hydrocarbons, 

 alcohols, acetales, ethers, esters, lactones, alde- 

 hydes, ketones, phenols and phenolic ethers, 

 nitro compounds, and bases. The methods of 

 preparation and the characteristic reactions 

 of the various groups are given. 



The references to the literature throughout 

 are numerous. The importance of the patent 

 literature is recognized, and not only are refer- 

 ences given to patents in the text, but there is 

 also a separate classified list of all German 

 patents covering methods of isolation or prepa- 

 ration of perfume substances. The different 

 European factories which manufacture per- 

 fumes are also noted. 



Trade statistics, however, are almost wholly 

 lacking. Many reports have been published 

 in recent years on the production of ethereal 

 oils and perfume substances in various parts 

 of the world, the consumption of flowers for 

 this purpose, cost of same, percentage of oil 

 yielded per pound of flowers, and so forth. 

 A resume of such data would have been in- 

 teresting. 



The book should prove a useful compilation 

 for all interested in this branch of organic 

 chemistry. 



Die diherischen Oele nach ihren chemischen 

 Bestandteilen unter BerUshsich.iigung der 

 geschichtlichen EntivicMung. By Dr. F. 

 W. Semmler, ord. Honorarprofessor an 

 der Universitat Greifswald. Leipzig, Von 



, Veit & Company. 1905. Erste Band; 

 , Erste Lieferung; Ailgemeiner Teil. Large 



