May 27, 1920] 



NATURE 



383 



amongf the nine leadings industries of the country, 

 it is only within recent years that even enlightened 

 employers have begun to realise that "chemistry 

 and physics play a riiost important part in the 

 various operations used in the production of yarns 

 and finished pieces." 



All this may be very true. But it is equally 

 true that the hard-headed Yorkshire manufacturer 

 who turns over the pages of this well-printed and 

 handsomely illustrated book will be slow to per- 

 ceive wherein it bears directly upon his industry. 

 He will be apt to think that the kinetic theory 

 and Avogadro's hypothesis have as little to do 

 with woollens and worsteds as the binomial 

 theorem has with the common pump. There is 

 not the slightest intention to minimise the import- 

 ance of a knowledge of the principles upon which 

 chemistry as a science is based, or to depreciate 

 its value when applied to industry. It is admitted, 

 of course, that no technologist is adequately 

 trained who is wholly ignorant of the science. 

 But in compiling a text-book which would seem to 

 be mainly directed to the wor'k of their classes 

 the authors have attempted too much. They have 

 mixed up purely elementary doctrinal chemistry 

 with applications involving a very different 

 kind of knowledge. The problems of textile 

 chemistry are far more recondite than their asso- 

 ciation with rudimentary chemistry, as in this 

 book, would seem to imply. We have no fault 

 to find with the book as a text-book to accom- 

 pany an experimental course of evening lectures 

 such as the authors are engaged in giving, except 

 that its price will probably be beyond the means 

 of the ordinary evening-class student. 



The course as set out in the book is well arranged, 

 and it is intended that the pupils shall themselves 

 perform many of the elementary experiments de- 

 scribed, presumably in a laboratory class. There 

 is no doubt that if they work through the list 

 under competent direction they will acquire a 

 considerable amount of mformation, and gain 

 some proficiency in chemical manipulation. No 

 special experiments are described in the section 

 devoted to the systematic study of the non-metals 

 and their important compounds, or in that con- 

 cerned with the chennstry of the hydro-carbons 

 and their derivatives, but the student is directed 

 to " pick out the portions which are suitable for 

 experimental illustration with the apparatus at 

 his command " — a direction which, it may be 

 hoped, will strengthen any latent power of original 

 investigation that he may possess. 



The scope of the teaching has presumably been 



limited to what has been found to be practicable in 



such courses of evening-class instruction as are 



possible in the institutions with which the authors 



NO. 2639, VOL. 105I 



are connected, and there can be no doubt that if 

 the beginner faithfully follows the teaching and 

 supplements it by reading the " larger and more 

 specialised works " to which he is referred, and 

 which, it is to be hoped, he will find in the libraries 

 of the schools to which he may be attached, he 

 will have acquired a very fair acquaintance with 

 the elements of chemistry. But as he pursues his 

 reading, and enters upon the perusal of the more 

 specialised works on the chemistry of textiles, he 

 will realise that he has got no further than the 

 alphabet of the subject. After all, a knowledge of 

 the alphabet is an essential step, and it may be 

 that the authors, pace the title of their book, have 

 aimed no higher. The time will come when our 

 technical schools will not mix up elementary with 

 applied teaching, but make each section inde- 

 pendent. Applied chemistry must of course be 

 based on elementary and theoretical chemistry, 

 but there are no short cuts to proficiency in any 

 one branch, and it is a bad system of instruction 

 which fosters the idea that there can be. 



(3) In about ninety small octavo pages Mr. J. B. 

 Robertson, lecturer in chemistry at the South 

 African School of Mines and Technology, 

 Johannesburg, has sought to give an account of 

 the chemistry of coal. His title may be held to 

 imply more than his little monograph actually 

 covers, as he confines himself to a very limited 

 portion of what in reality is a very wide field, 

 and has very little to say respecting the chemical 

 derivatives of coal, except to the extent that 

 they may be supposed to throw light on the nature 

 ctf the proximate constituents of coal. In five short 

 chapters, or sections, Mr. Robertson discusses 

 the mode of occurrence of coal, its origin, and 

 the various methods of classifying it; the action 

 of solvents, e.g. benzene and pyridine, etc., upon 

 the coal substance; its oxidation and destructive 

 distillation. The summaries are exceedingly 

 short, but they are accurate and fairly up-to-date, 

 and at least serve to show how much remains to 

 be done before the real chemical nature of coal is 

 elucidated. Practically all that we know at 

 present is that coal consists of a variable and 

 indefinite mixture of at least two constituents, 

 one of which appears to be a degradation product 

 of cellulose, and the other a resinoid substance 

 which can be extracted by appropriate solvents ; 

 and that it is upon the relative proportion of these 

 constituents that the technical value and indus- 

 trial applications of coal largely depend. But 

 the precise nature of these constituents is as yet 

 very imperfectly defined, and the suggestions that 

 have been made as to their origin are little more 

 than surmises. 



The most detailed sections of the book relate 



