REVIEWS 495 



nitrogen fertilisers are discussed at some length, and a very good summary of 

 the synthetic ammonia and nitrate processes is given. A considerable amount 

 of space is devoted to the phosphatic manures, as becomes their importance, 

 and incidentally the growth of the sulphuric acid industry is commented on, 

 together with the possible means of disposing of the excessive quantities 

 produced as a consequence of the war ; in this connection reference is also 

 made to the use for agricultural purposes of dilute sulphuric acid as a spray 

 for killing weeds, although, of course, it is not suggested that this would 

 account for any considerable quantities. In a section devoted to the valua- 

 tion of fertilisers will be found an interesting discussion of the economic 

 aspect of the question from the point of view of the cost to the farmer of 

 his fertilisers, together with some practical hints as to how he could reduce 

 his costs by suitable storage and economy of carriage. There are, furthermore, 

 special sections dealing with manure for special soils and climates and also 

 manures suited for special crops. The writer is evidently fully alive to all 

 the recent developments of the industry, as is witnessed by his inclusion of 

 most of the processes employed during the war, and in more than one place he 

 emphasises the importance to the country of scientific effort and the utilisa- 

 tion of modern appliances. His views on the possibilities of the manufacture 

 of fertilisers may be stated in his own words : " It is one of the problems 

 of the future to convert some of this war enterprise into useful peace industry, 

 and to this end the fertiliser trade might take some active part." P. H. 



Everyday Chemistry. By W. Robinson, B.Sc, Instructor in Chemistry and 

 Physics, Officers' School of Education, Oxford. [Pp. viii + 138, with 

 iUustrations and diagrams.] (London : Methuen & Co., 1920. Price 

 3s. 6d. net.) 



This little work is the outcome of the endeavour made at the end of the war 

 to provide an outline course of chemistry for the use of those officers engaged 

 in delivering short courses to the rank and file of the army. 



Obviously the problem was no easy one, as the men could hardly be treated 

 as children, so that the usual line of approach would not serve, and any attempt 

 at systematic study would create an interest in the few only. Consequently 

 a method of approach along three main lines was adopted in the school : 

 (i) History, (2) Common Objects, (3) Industrial Interests ; and this method 

 has been embodied in the present book, which is essentially a teacher's book 

 and is not intended to be used as a textbook by pupils working alone ; it is, 

 in fact, more or less in the nature of lecture notes. 



As the author points out, adult education does not cease with the army 

 scheme, and the hope is expressed that the book may be of use not only in 

 continuation schools but also in Study Circles, W.E.A. classes, where teachers 

 are troubled not only with the mere imparting of knowledge but with the 

 greater problem of how to use this subject as an educational instrument. 



F. A. M. 



GEOLOGY 



The Geology of India for Students. By D. N. Wadia, M. A., B.Sc. [Pp. xx -f 

 398, with 20 plates and 37 figures.] (London : Macmillan & Co., 1919. 

 Price 1 8s. net.) 



As it is now more than a quarter of a century since Oldham's book on tYieGeology 

 oj India appeared, and as during that period a large volume of work on the 

 subject has been pubhshed in the Records of the Geological Survey of India and 

 elsewhere, there is abundant need for the publication of a textbook incorporat- 

 ing the recent work. The aim of the author has been to provide for the stu- 

 dents in the Indian colleges a summary of what is known, at the present time, 

 of the geology of the country, and thvjs to save theui the trouble of gearohing 



