September i6, 1920] 



NATURE 



75 



and profits, so that the workpeople can determine 

 whether they are being^ fairly treated or not, and 

 at the same time the consumer can ascertain 

 whether the prices he is charged are due in any 

 degree to profiteering. As Mr. Johnston rightly 

 points out, "the first essential to a better under- 

 standing between Capital and Labour is that all 

 the cards should be laid on the table." 



H. M. V. 



Fuel Economy. 



The Use of Low-grade and Waste Fuels for 

 Power Generation. By John B. C. Kershaw. 

 Pp. X + 202. (London: Constable and Co., 

 Ltd., 1920.) Price 17^. net. 



THE great increase in the cost of coal has 

 naturally directed the attention of users of 

 fuel to the question of fuel economy, the possibili- 

 ties of which lie in two directions — the utilisation 

 of lower-grade fuels and waste combustible 

 material, and the more efficient utilisation of all 

 fuels. Mr. Kershaw's book deals adequately with 

 both these aspects of this important question. His 

 earlier chapters are devoted to the consideration 

 of peat, wood waste, small coal and washery 

 waste, and other minor combustibles. In his 

 second section he deals with fuel sampling and 

 analysis and with the scientific control of combus- 

 tion in practice. 



.Mr. Kershaw defines low-grade solid fuel as 

 containing more than 25 per cent, of ash and 

 10 per cent, of moisture, or, in all, 35 per cent, of 

 incombustible material. The cynic may remark 

 that such a definition covers most of the coal at 

 present marketed ! Small coal, however, no matter 

 what its ash and moisture content, is also "low 

 grade," and the author includes all coal and coke 

 passing a J-in. mesh sieve. 



Means are available, and Mr. Kershaw describes 

 them clearly and discusses their merits lucidly, by 

 which the lower-grade fuels may be utilised, but 

 possibly, because of present economic conditions, 

 the more general utilisation of low-grade coal and 

 colliery refuse will be confined to the large, cen- 

 tralised power schemes which have been recom- 

 ■innded, and individual consumers will more 

 >l)ii ifically seek economy in the better utilisation 

 of the class of fuel they have been accustomed to 

 use, and for which their plants can be adapted 

 with but little expenditure. Mr. Kershaw's treat- 

 ment of this side of the question is adequate and 

 practical, and he is to be congratulated on pro- 

 ducing this small volume at this opportune 

 moment, for it is one to command the attention 

 of all interested in the use of fuel for every indus- 

 trial purpose. 



NO. 2655, VOL. iObj 



Text-books of Chemistry, 

 (i) An Introductory Course in Quantitative 

 Chemical Analysis, with Expla»iatory Xotcs, 

 Stoichiometrical Problems, and Questions. By 

 Prof. G. McPhail Smith. Pp. x -1-206. (New 

 York : The Macmillan Co. ; London : Macmillan 

 and Co., Ltd., 1919.) Price 9.';. net. 



(2) Quantitative Analysis by Electrolysis. By .\. 

 Classen, with the co-operation of H. Cloeren. 

 Revised, rearranged, and enlarged English 

 edition by Prof. W. T. Hall. Pp. xiii + 346. 

 (New York : J. Wiley and Sons, Inc. ; London : 

 Chapman and Hall, Ltd., 1919.) Price 17s. 6d. 

 net. 



(3) Industrial Organic Analysis: For the Use of 

 Technical and .Analytical Chemists and 

 Students. By Paul S. .Arup. Second edition, 

 revised and enlarged. Pp. xi + 471. (London: 

 J. and .\. Churchill, 1920.) Price 12s. 6d. net. 



(4) A Foundation Course in Chemistry: For 

 Students of .Agriculture and Technology. By 

 J. W. Dodgson and J. Alan Murray. Second 

 edition, thoroughly revised. Pp. xii-i-241. 

 (London : Hodder and Stoughton, Ltd., 1920.) 

 Price 65. 6d. net. 



(5) Chemistry in Everyday Life: Opportunities in 

 Chemistry. By E. Hendrick. Pp. xii-fio2. 

 (London : University of London Press, Ltd., 

 igig.) Price 3s. 6d. net. 



IN the multiplicity of text-books one naturally 

 looks for evidence of the trend of progress as 

 demonstrated in new editions and new volumes. 

 We want to find the aim of the author and why 

 he has considered it desirable to add one more to 

 the books that are already so many that the 

 teacher and the student find it difficult to select 

 the one that will suit them best. 



(i) Prof. Smith says of his manual that it is 

 for those who have completed courses in element- 

 ary chemistry and qualitative analysis and are 

 beginning work in quantitative analysis. \Vc 

 are glad to see, so far as this is evidence of it, 

 a return to the natural sequence of quantitative 

 following qualitative work. The student at this 

 stage ought to be able to appreciate the intro- 

 ductory section in which the author, after some 

 excellent advice, proceeds to consider the balance, 

 its use and care, methods of weighing, the cali- 

 bration of weights, various errors and their 

 elimination ; the precipitation, filtering, and wash- 

 ing of precipitates, in which he uses the theories 

 of mwlern physical chemistry ; drying, ignition, 

 evaporation, and the use and calibration of volu- 

 metric apparatus. The student is thus well pre- 

 pared to work intelligently, but throughout 

 the book, although llic instructions are definite, 

 almost every dire<-tii ' ompanied with ihr 



