lOO 



JVA TURE 



[May 30, 1 90 1 



bases. A piece is to be heated in an ignition tube, when 

 t may be seen to melt. We now pass to the heading 

 "Sodium Chloride, NaCl." Some of the caustic soda 

 solution is to be neutralised with hydrochloric acid. 

 Sodium chloride is said to be formed and the student is 

 to write the equation and to make calculations as to the 

 concentration and normality of the HCl solution. The 

 solution of sodium chloride is evaporated until it crystal- 

 lises, and the process is also observed under the micro- 

 scope. The salt is tasted, some put into the flame and 

 some treated with sulphuric acid. The next preparation 

 is that of hydrochloric acid in quantity. The solution of 

 the gas in water is to be examined on the same lines as 

 the caustic soda solution. Some dilute acid and then 

 some strong acid are to be heated in a test-tube, and the 

 student is informed what variations of concentration have 

 occurred. Then follows a disquisition on acids, bases 

 and salts. 



Space will not permit of further description of the course 

 in detail. After the discussion of acids, bases and salts, 

 we have the tests for hydrochloric acid ; sulphuric acid 

 follows, with remarks on its constitutional formula, its 

 action on metals, &c. Nitric acid, hydrogen sulphide, 

 carbonic acid, phosphoric acid and boric acid bring us, 

 for the time being, to the end of the acids. Then come 

 potassium, sodium and ammonium, followed by a discus- 

 sion of their analytical separation. The rest of the book 

 is much on the same plan. It ends with a chapter on 

 the modern theory of solution (which is not employed 

 in the body of the work) and details of the ordinary 

 analytical separation. Tables of reagents, some density 

 tables and a map of spectra are added. 



The impression gained on reading through the book is 

 that we have to do with a genuine attempt to combine 

 accurate practical work with accurate theoretical know- 

 ledge. There is a great deal of admirable matter that is 

 not usually to be found in books on practical chemistry. 

 On the other hand, the style of the book is haphazard in 

 the extreme and affords an example of logical detail with- 

 out logical plan. There is also a constant variation of 

 level in the instruction. A student who calculates the 

 normality of a caustic soda solution and is soon after to 

 have his attention briefly drawn to the possible constitu- 

 tional formute of sulphuric acid is subjected to the indig- 

 nity of trying the effect of his soda solution on litmus and 

 turmeric paper. Then again, the student is told a great 

 many things that he might easily and profitably establish 

 by experiment, such as the fact that caustic soda exposed 

 to air actually has absorbed carbon dioxide. It is desir- 

 able, no doubt, that the student of practical chemistry 

 should understand the behaviour of concentrated and 

 dilute acids on boiling, but the* mere statistics of the 

 subject are no explanation, and practical work on the 

 subject should be linked to the simple generalisations 

 that illuminate it. 



It would not be right to dwell further on the weaker 

 features of a book which, on the whole, is much more 

 rational and luminous than the great majority of works 

 on practical chemistry. It must be admitted that the 

 task of writing a combined theoretical and practical work 

 on chemistry is very difficult, and that Dr. Knoevenagel 

 has given us a book that well deserves the attention of 

 teachers. .\. S. 



NO. 1648, VOL, 64I 



OUR BOOK SHELF. 

 Central Electrical Stations : their Design, Organisation 

 and Matiagement. By C. H. Wordingham. Pp. 

 xvi 4-496. (London: C. Griffin and Co., Ltd., 1901.) 

 Price 24^. net. 

 We venture to think that few, if any, persons could 

 be found better qualified than Mr. Wordingham to 

 write a treatise on central electrical stations, and there 

 can be no question but that he has carried out his task 

 in a very thorough and competent manner in the book 

 before us. Whilst endeavouring to deal with practically 

 every subject which enters into the organisation or 

 management of a central station, the author has wisely 

 given prominence to those matters which are not to be 

 found already in other books. The central station 

 engineer, especially if he have charge of a large gene- 

 rating station such as are now becoming more and more 

 numerous, must be a man of wide experience and attain- 

 ments, and it would be impossible to compress into one 

 volume all the knowledge that he requires in his profes- 

 sion, quite apart from the consideration that such know- 

 ledge cannot be obtained from books alone. But whereas 

 there is plenty of literature already dealing with the 

 separate branches, such as steam engineering, dynamos, 

 &c., there was none, until now, dealing thoroughly with 

 the subject as a whole. Those who have charge of 

 central stations, or those who are ambitious of attaining 

 this distinction, will find Mr. Wordingham's book a very 

 valuable guide. 



Central station work has for long attracted a large 

 number of young engineers, the rapid growth due to the 

 spread of electric lighting offering great chances of ad- 

 vancement. It is true, perhaps, that now, as Mr. Word- 

 ingham says, the practice is becoming more settled and 

 stereotyped and that entry into this branch of the pro- 

 fession will require a somewhat longer apprenticeship 

 than has been usual hitherto ; but this is not likely to 

 discourage many, for the prospects for the future are 

 even brighter than they were in the past. Large electric 

 power schemes and the certain adoption of electric 

 traction for tramways and urban railways point to an 

 expansion which is sure to be both large and rapid for 

 a long time to come. Those who are anxious to take part 

 in this development cannot do better than study the 

 book before us with care and attention. There is a fair 

 amount in the book that is controversial, but this renders 

 it none the less valuable ; if the student is not always 

 inclined to agree with the author, he will at least be 

 benefited by the careful consideration of opinions derived 

 from so wide an experience. Some may think, perhaps, 

 that the clerical side of the organisation is given an un- 

 due amount of space ; this is, however, only in accord- 

 ance with the scheme of the work, seeing that this is 

 one of those subjects not to be found in other books. 

 Moreover, the student is too prone to think that scientific 

 knowledge alone is sufficient to make a successful engineer 

 and to underrate the importance of a sound and systematic 

 organisation. 



Hints to Travellers. Edited by John Coles. 2 vols. Pp. 

 x-l-436 and viii-l-266. (London: The Royal Geo- 

 graphical Society, 1901.) 

 This useful work, of which the present issue is the eighth 

 edition, has now been divided into two volumes. The 

 first is devoted to the various problems of surveying and 

 practical astronomy, and important additions have been 

 made to the matter brought over from the last edition. 

 The new chapters include a considerable expansion of 

 the article on surveying, ordinary and photographic, a 

 graphic method of predicting the occultation of stars by 

 the moon, and an entire set of tables by the aid of 

 which, and the Nautical Almanac, the traveller will 

 have all the materials for computing the results of his 

 observations. 



