846 



SCIENCE. 



[N. S. Vol. XIV. No. 361. 



lungs coefiBcient) 



oil 



of the many indifferent 



water 



and basic anaesthetics. His studies led him to 

 the conclusion that the narcotic power of a 

 compound depends in the first place upon its 

 division-coefficient between the aqueous medi- 

 um and the cholesterin-lecithin solvents of 

 the orgaaism, provided the absolute solubility 

 of the compound in the cholesterin-lecithin 

 solvent is not below a certain minimum. 



In the second part detailed descriptions and 

 tables are given of the numerous experiments 

 made on a great many compounds, establishing 

 in each one its division-coefficient and its nar- 

 cotic power. The compounds comprise indif- 

 ferent and basic narcotics, also antiseptics 

 and antipj'^retics which possess more or less 

 anaesthetic powers as secondary eflfects. The 

 author draws from his numerous experiments 

 the conclusion that the longer and the less 

 branched the carbon chains of a compound are, 

 the stronger is its narcotic power, and that the 

 substitution of a hydrogen atom by a hydroxyl 

 group diminishes, and the substitution by an 

 alkyl group increases, the narcotic power of a 

 compound. Overton thinks that the indifferent 

 narcotics interfere probably in a physical way 

 with the cholesterin and lecithin of the cells, 

 while the basic narcotics interfere also with the 

 protoplasm of the cell, hence the greater cling- 

 ing of the latter group of narcotics to the cells 

 and their deleterious effects. 



Overton's book is a very valuable contribu- 

 tion to biology and pharmacology ; it opens 

 new fields and new methods of research and 

 will prove to be a fruitful stimulus to student 

 and investigator. 



S. J. Meltzer. 

 New Youk. 



Les mati^res colorantes naturelles. By V. 

 Thomas (Chef des travaux de chimie appliquee 

 h, la Faculte des Sciences de Paris). Une pub- 

 lication de I'Encyclopedie Scientifique des 

 Aide-Memoire. Publiee par Gauthier-Villars, 

 Paris, sous la direction de M. L6aut6 (Membre 

 de rinstitut). Pp. 180. 



It is probable that no department of chem- 

 istry, during the past thirty years, has experi- 

 enced a more marvelous development and 



elaboration than that relating to the artificial 

 dyestuffs. At the present time these synthetic 

 dyes are numbered by the thousand, and millions 

 of dollars are invested in their commercial pro- 

 duction. Two of the largest chemical factories 

 of the world are devoted to this industry, one 

 employing over 200 trained chemists, the other 

 over 160, practically all of them Ph.D. men 

 from the universities. The relation between 

 the structure of these dyestuffs and their tinc- 

 torial value has been definitely established for 

 most classes of artificial colors, and the litera- 

 ture of the subject is vast in extent. 



The result of this tremendous activity in the 

 field of artificial colors has been that the natural 

 colors have been correspondingly neglected, 

 and it is only within quite recent years that at- 

 tention has again been directed to these sub- 

 stances, many of which have been familiar 

 since ancient times. These scattered researches 

 upon the tinctorial constituents of plants used 

 in dyeing have been collected, digested, and 

 the results presented in a condensed form by 

 the author. The work is ably and carefully 

 done, the chapter upon the Flavone Colors 

 being especially praiseworthy. 



In this volume the author treats only those 

 natural coloring matters which are commonly 

 regarded as derivatives of benzophenone, xan- 

 thone or flavone, thus including the majority 

 of the natural yellow dyes. 



Each chapter opens with general statements 

 concerning that particular group of colors, its 

 history, development, etc. This is followed by 

 a detailed description of the individual colors, 

 giving history, preparation, properties, tinc- 

 torial value, etc., the reactions and syntheses 

 by which the constitutional formula has been 

 elucidated being clearly and concisely explained. 

 References to original articles are numerous, 

 and in some cases (e. g., syntheses in the fla- 

 vone group) quite extensive. 



The separate chapters deal with the follow- 

 ing colors ? 



I. Derivatives of benzophenone. — Maclurin 

 and derivatives, catechin and derivatives, 

 kinoin. 



II. Derivatives of xanthone. — Indian yellow, 

 euxanthone, gentisin and gentisein, datisce- 

 tin, paradatiscetiu. 



