DISCOVERY 



1C7 



to the young students. Some day all these ideas and the 

 jargon in which they are expressed will be out of date as 

 the doctrine of phlogiston. That was a useful idea for a 

 few years ; it made people think." But with regard to 

 the second sentence, how can Chymist or anyone else say 

 that ? The future may decide in favour of the theory 

 of ionisation, and regard as ver}' trivial indeed present 

 objections to it. But who can say ? Someone who 

 argues very like Chymist attacked the disintegration 

 tlieory of radio-activity twenty years ago. The theory 

 tt.inds now as it did then, but where are now the objec- 

 tions ? It is they that lie on the dust -heap where " the 

 elixir of life " lies dead and " phlogiston " rets. 



The Phase-Rule and its Applications. By Alex.\nder 

 FiNDLAY, M.A., D.Sc, F.I.C. (Longmans, Green & 

 Co., I05. 6d.) 

 The fifth edition of this excellent work, the most 

 popular among students of Sir William Ramsay's series 

 of Textbooks of Physical Chemistry, includes the notable 

 additions to the subject since the time of the last edition, 

 1914. These are principally in connection with hetero- 

 geneous equilibria. In consequence there has been much 

 revision and addition. The sections on sulphur and 

 phosphorus, for example, have been rewTitten, and that 

 on iron-carbon alloys has been drastically revised in the 

 light of recent work. Graphical methods of representa- 

 tion, especially those suggested by Janecke, have been 

 expounded more full)' here than in the earlier editions. 

 And in other ways there are improvements which add to 

 the usefulness of the book. 



Maps and Survey. By Arthur R. Hinks, C.B.E., 

 M.A., F.R.S. Second Edition. (Cambridge Univer- 

 sity Press, I2S. 6d.) 



Maps and Survey, by the Secretary of the Royal 

 Geographical Society, first appeared in 1913, when the 

 author lectured in the department of Geography at 

 Cambridge. The titles of its chapters then were ilaps. 

 Map Analysis, Route Traversing, Simple Land Survey, 

 Compass and Plane Table Sketching, Topographical 

 Survey, Geodetic Survey, and Survey Instruments. The 

 book is now reissued wdth the original chapters as they 

 stand supplemented with one containing a few necessary 

 corrections and additions. To these have been added new 

 chapters — A Further Chapter on Maps, Maps and Survey 

 in War, and New Methods of Survey — so that the work 

 might include a description of the very valuable advances 

 made during the years of war, and be up-to-date. 



The book is now one which students of geography 

 may read for accurate information on the subject it 

 describes. It is clear and comprehensive ; the author 

 is and has been in a position to obtain up-to-date informa- 

 tion, and he is one who loves accuracy and carefulness of 

 statement for their own sakes. The first of the new 

 chapters describes matters recently under discussion at 

 the Geographical Society, such as the international map 

 on the scale one to a million, flying maps, and the spelling 

 of place-names ; the second gives an account of the work 

 of " Maps " during the war — survey for artillery, f.ash- 

 spotting, sound-ranging, etc.; and the third subjects like 



mapping from air photographs, and instruments for 

 stereoscopic survey. 



A Textbook of Ore Dressing. By S. J. Truscott, 

 A.R.S.M., M.I.M.M. (Macmillan & Co., Ltd., 405.) 

 An informed, comprehensive, and well-illustrated 

 treatise on the subject by the professor of mining at the 

 Imperial College of Science and Technology', the more 

 valuable and useful because the author in his day has 

 been a practical man. The dedication (in the first nine 

 words of the Absolution in the Praj'er Book) might, one 

 reader at least thinks, have been expressed differently, 

 or, better, since the book is on technology', omitted 

 altogether. 



Chemical Technology and Analysis of Oils, Fats, and 

 Waxes. Vol. III. By Dr. J. Lewkowitsch, M.A., 

 F.I.C. Sixth Edition. Revised by George H. 

 Warburton. (Macmillan & Co., Ltd., 36s.) 



This \-olume completes the revised edition of Dr. 

 Lewkowitsch's standard work of reference on the subject, 

 and contains chapters on the technology of manufactured 

 oils, fats, and waxes, and on the technology of waste oils, 

 fats, and waxes, and the commercial products derived 

 from them. 



Books Received 



(Mention in this column does not preclude a review. ) 

 ANTHROPOLOGY AND ARCHEOLOGY 



The Ancient Egyptians and the Origin of Civilisation. 

 By Prof. G. Elliot Smith, M.A., M.D., Litt.D., 

 F.R.S. New and Revised Edition. (London and 

 New York : Harper & Bros., 6s.) 



The Bakitara or Banyero. By John Roscoe. (Cam- 

 bridge : at the University Press, 255.) 



SCIENCE 



Aspects of Science. By J. W. N. Sullivan. (Richard 



Cobden-Sanderson, 6s.) 

 Great and Small Things. By Sir Ray Lankester, 



K.C.B., F.R.S. (Methuen & Co., Ltd., 7s. 6d.) 

 Electrons, Electric Waves, and Wireless Telephony. By 



J. A. Fleming, M.A., D.Sc, F.R.S. (The Wireless 



Press, Ltd., 7s. td.) 

 The Radio Experimenter's Handbook. By Philip R. 



Coursey, B.Sc. Part II. (The Wireless Press, 



Ltd., 3s. 6d.) 

 How to build Amateur Valve Stations. By P. R. Coursey, 



B.Sc. (The Wireless Press, 3s. 6d.) 

 Special Steels. By Thos. H. Burnham, B.Sc. (Sir 



Isaac Pitman & Sons, Ltd., 5s. net.) 

 Plant and Flower Forms. By E. J. G. Kirkwood. 



(Sidgwick & Jackson, Ltd., 7s. 6d.) 

 Interfacial Forces and Phenomena in Physiology. By Sir 



William M. B.\yliss. (Methuen & Co., 7s. 6d.) 

 Advanced Practical Physics for Students. By B. L. 



WoRSNOP and H. J. Flint. (Methuen & Co., 21s.) 



