October 21, 19 15] 



NATURE 



197 



callous necromancer who has cut himself off from 

 communion with his fellows, and has thereby lost 

 the throbbing^ and compassionate heart of a full 

 life ; he is a Faust who has not yet made a bargain 

 with Mephistopheles, and is therefore without 

 human interest. Scientific and humanistic studies 

 are, indeed, supposed to be antipathetic and to 

 represent opposing qualities; so that it has become 

 common to associate science with all that is cold 

 and mechanistic in our being, and to believe that 

 the development of the more spiritual parts of 

 man's nature belongs essentially to other depart- 

 ments of intellectual activity. 



When scientific work is undertaken solely with 

 the object of commercial gain, its correlative is 

 selfishness ; when it is confined to the path of 

 narrow specialisation, it leads to arrogance ; and 

 when its purpose is materialistic domination, with- 

 out regard to the nobler deeds of humanity, it is 

 a social danger and may become an excuse for 

 learned barbarity. But research is rarely inspired 

 by these motives, nor does devotion to it necessarily 

 inhibit interest in other notes with which a well- 

 balanced mind should be in resonance. Direct 

 contact with Nature and inquiry into her laws do, 

 however, produce a habit of mind which cannot 

 be acquired in literary fields, and they are asso- 

 ciated with a wide outlook on life more often 

 than is popularly supposed. Science is not only 

 able to increase the comforts of life and add to 

 material welfare, but also to inspire the highest 

 ethical thought and action ; and a prominent place 

 should be given to it in all stages of educational 

 work as much on account of its ennobling in- 

 fluence as because it is a creator of riches. 



Success in science means the birth of new know- 

 ledge. Patient observation and productive think- 

 Iing are what the world needs for progress, and 

 what true scientific study demands. There are 

 J now so many opportunities of obtaining ready- 

 I made opinions that the habits of independent 

 i thought, caution in accepting assertion, and 

 I critical inquiry into evidence, are suffering atrophy 

 • by disuse. Vox populi, vox Dei, may be a sound 

 ; democratic principle for political platforms, but it 

 ' stands for nothing in science. The men who have 

 advanced the human race throughout the ages are 

 they who have stood for individuality as against 

 the voice of the crowd. We need such leaders 

 now, men who will guide the people instead of 

 waiting for a mandate from them before embark- 

 ing upon any enterprise; and we need, above all, 

 that the chief officials of departments of State 

 should have had a training in scientific methods 

 before being entrusted with the control of national 

 NO. 2399, VOL. 96] 



affairs. While indifference to these things is the 

 distinguishing characteristic of our statesmen and 

 administrative officers, it is useless to expect that 

 the nation's business will be conducted efficiently 

 or its scientific forces be organised on the large 

 sc^le which modern conditions demand. 



ANALYTICAL CONTROL OF MODERN 

 DYES. 



The Analysis of Dyestuffs and their Identification 

 in Dyed and Coloured Materials, Lake Pig- 

 ments, Foodstuffs, etc. By Prof. A. G. Green. 

 Pp. ix+144. (London: C. Griffin and Co., 

 Ltd., 1915.) Price 8s. 6d. net. 



MODERN developments in the manu- 

 facture of synthetic colouring matters 

 have now rendered it possible for the dyer to 

 obtain any desired shade of colour in many 

 different ways, but the suitability of the colour 

 to the conditions under which the dyed material 

 is to be employed depends entirely on the blend 

 of dyes selected. It is evident that some ana- 

 lytical control is desirable in order that the most 

 favourable result can be guaranteed. 



Largely owing to the labours, extending over 

 many years, of the author and his collaborators, 

 a method has now been devised which is suffi- 

 ciently comprehensive and elastic to cope not only 

 with all the known dyes, but also with mixtures 

 of these substances. 



The three introductory chapters of this work 

 treat of the chemistry of colouring matters and 

 of the classification of these materials according 

 to their chemical and tinctorial properties. In 

 regard to theories of the colour of organic dyes. 

 Prof. Green seems still to be a faithful adherent 

 of the " quinonoid " hypothesis, in spite of the 

 fact that he has himself discovered at least one 

 dyestuff, namely, primuline (p. 21), to which he 

 has not ascribed a " quinonoid " chemical con- 

 stitution. It should, however, be added that the 

 practical scheme of analysis presented in this 

 manual is based on the tinctorial properties of 

 the dyes, and not on hypothetical views in regard 

 to their chemical structure. An interesting table 

 serves as the summary of these introductory 

 chapters, in which the chief series of colouring 

 matters arc doubly classified in accordance with 

 their chemical nature and their dyeing properties. 

 This tabulation indicates in a striking manner 

 the lines along which future research may lead 

 to many still missing groups of dyes. 



The analysis of the dyes in bulk leads to a 

 division into four main classes, in which solu- 

 bility in water, affinity for unmordanted cotton, 

 and precipitation by tannin form the distinctive 



