REVIEWS. 



AVIATION. 



Aviation. — By Algernon E. Berriman (late Technical 

 Editor of Flight). 360 pages. 32 illustrations. 6j-in.X 5j-in. 



(Methuen & Co. Price 10/6 net.) 



Mr. Berriman has attempted a Herculean task. He has 

 not only endeavoured to cover the entire ground of a 

 tremendous subject, but he has aimed at producing a book 

 that shall appeal to the whole range of possible readers — from 

 the tyro whose knowledge of flight is limited to a single visit to 

 an aerodrome, to the experienced aviator desirous of under- 

 standing the rationale of his movements in the air, or the 

 aeroplane constructor aiming at the perfect machine. 



In a measure the author has accomplished the feat. In 

 one sentence he explains that an aeroplane does not flap its 

 wings ; in another he becomes severely technical over the 

 differential negative warp. Some really admirable simple 

 examples and experiments, that the schoolboy will delight 

 in, are followed by formulae of Pressure and Resistance 

 Constants. This is well enough, but the reader of the 

 entire volume is left wondering whether the attempt has 

 really been worth while, or whether the schoolboy and the 

 aviator may not both be slightly disappointed. 



The only conceivable way in which such a task could be 

 accomplished is in a series of separate articles, and it is 

 of this that the volume with its twenty-four appendices really 

 consists. But the arrangement of these chapters might 

 well have been improved upon. The chronology is inten- 

 tionally turned upside down, but the result is a loss of 

 sequence and coherence. Many things come over twice ; nor 

 does the choice of subjects always seem wise. A description 

 of the various makes of aeroplanes would have been more 

 interesting than the Official Report of the Military Trials 

 of 1912. 



Nevertheless the book is inspiring and one to delve into ; 

 for it is full of good things. The debt that aviation owes to 

 Sir George Cayley is acknowledged more fully than ever 

 before, and it is pointed out how aeroplane gliders might have 

 been in use centuries before any sort of engine was known. 

 " If the brave spirits of those times had sought to emulate the 

 soaring feats of birds, there is very little doubt but that a man at 

 the present day would be as much at home in the air as he is, 

 for example, in the water." 



It may be questioned, by the way, if Mr. Berriman's 

 description of the sensation of flying is the general experi- 

 ence. It is not the writer's, at any rate. 



If this book is not wholly satisfying, it is at least brimful 

 of information and interest. It is extremely well illustrated 

 and produced. 



G. B. 



CHEMISTRY. 



Rubber and Rubber Planting. — By R. H. Lock, D.Sc. 

 245 pages. 32 illustrations. 7i-in. X4|-in. 



(The Cambridge University Press. Price 5/- net.) 



So many industries are now dependent upon a plentiful 

 supply of rubber that a book which describes in a simple 

 manner the nature of indiarubber and the science and practice 

 of planting the trees, should meet with a wide welcome. The 

 authoritative account given by Dr. Lock is not only extremely 

 interesting to read, but should also be of real value to the 

 prospective rubber planter and to those who wish to interpret 

 the prospectus of a rubber company. 



Separate chapters are devoted to the physiology of the 

 latex, planting and harvesting operations, and the pests and 

 diseases to which the plant is liable. The book does not 

 profess to deal exhaustively with the chemistry of the subject, 

 but an outline is given at sufficient length for a non-chemical 

 reader, while there is a clear summary of the different pro- 

 cesses used in the manufacture of rubber goods. 



The description of the industry gains much by the illustra- 

 tions, which include ten full-page photographs of methods of 

 tapping the rubber, diseased trees, apparatus, and so on, 

 and excellent line drawings, specially made by Mr. Denton 

 Sayers, of the different species of rubber-producing plants. 



C. A. M. 



Osmotic Pressure.— By A. Findlay, D.Sc, F.I.C. 



84 pages. 2 illustrations. 9-in.X6-in. 



(Longmans. Green & Co. Price 2/6 net.) 



The latest addition to the Monographs on Inorganic and 

 Physical Chemistry is written by the general editor of the 

 series, and deals with the subject of osmosis upon similar lines 

 to those followed in the preceding monographs. Readers of 

 " Knowledge " will recall the wonderful osmotic forms 

 described by M. Leduc, and his remarkable theories as to the 

 part played by osmotic processes in the development of life. 

 It is another of the points of contact between physics, 

 chemistry, and biology, and biologists in particular will 

 welcome the appearance of a book which can be used as a 

 laboratory companion. The subject is not intended to be 

 exhaustively discussed, for the aim of the monographs in this 

 series is to summarise the present condition of knowledge in 

 each branch and to bring together the results of investigations 

 which are widely scattered in scientific publications all over 

 the world. References to the original papers and a full index 

 increase the value of the book to the practical worker, while 

 the general student of chemistry will here find an excellent 

 outline of this branch of physical chemistry. 



C. A. M. 



Organic Chemistry for Advanced Students. — By J. B. 

 Cohen, Ph.D., B.Sc, F.R.S. 427 pages. 8|-in.X5i-in. 



(Edward Arnold. Price 16/- net.) 



In this work Professor Cohen amplifies and extends the 

 course of lectures which he published six years ago, so as to 

 give, not only a general historical survey of the rise of organic 

 chemistry, but also an account of the recent researches 

 showing the connection between physical properties and 

 chemical structure. 



Although full references are given at the foot of each page 

 to the original publications quoted in the text, the book is 

 intended rather to guide the student in the direction he may 

 profitably explore than to serve as a reference handbook. 



Starting with an outline of the history down to Kekule's 

 theory, the author proceeds to discuss the valency of carbon, 

 and summarises the facts which tend to prove that, contrary 

 to the belief which was long regarded as almost an axiom, 

 carbon need not necessarily be tetravalent, but may be 

 tervalent or bivalent. 



In the following chapters full outlines are given of the 

 nature of organic reactions, of their dynamics, of the relation- 

 ship between physical properties and structure, and of colour 

 and structure, and the book concludes with a good index of 

 authors and a subject index. The various theories, which are 

 not infrequently in conflict, are discussed at sufficient length, 

 the arguments for and against them being fairly presented. 



It is difficult to overrate the value of this book to the 

 student. Organic chemistry was for far too long a time 

 merely a storehouse of an immense accumulation of facts 

 which were apparently uncorrelated. The aim of each 

 investigator was to prepare a new crystalline compound, and 

 so add another substance to the long list. But now the order 

 underlying all these disconnected facts is gradually being 

 unfolded, and this book of Professor Cohen will help all who 

 seek its aid to grasp the new conceptions which are modifying 

 the whole course of organic chemistry. 



C. A. M. 



447 



