November iS, 1922] 



NA TURE 



66- 



Patents for Inventions. By J. Ewart Walker and 

 R. Bruce Foster. Pp. xiii+377. (London : Sir 

 I. Pitman and Sons. Ltd., 1922.) 215. net. 



The authors of this book depart somewhat from the 

 usual manner of treating the subject of patent law. 

 After a brief introductory survey, they first deal with 

 the manner of obtaining a patent, detailing the pro- 

 cedure in the Patent Office and in possible opposition 

 proceedings. Their next concern is the establishment 

 in the courts of the validity of the patent, consideration 

 being given both to the general rules governing the 

 interpretation of patents and to the grounds upon 

 which the patent may be held invalid. Finally, the 

 [>i i\ ili ges and responsibilities associated with the 

 possession of a valid patent are discussed, the chapters 

 relating to this covering very fully the rights of the 

 patentee in respect of infringements, royalties, licences, 

 etc., and his liabilities as regards revocation and 

 compulsory licences. 



By presenting the subject in this sequence, the 

 principles underlying patent law are linked up in a 

 manner which can easily be followed. As, in addition, 

 the treatment throughout is clear and concise and 

 avoids undue stress upon legal technicalities, the book 

 should commend itself not only to legal practitioners 

 but also to business men, directors of industrial re- 

 search, and others who are interested in the protection 

 and commercial exploitation of inventions. 



An appendix, which extends to a little over half the 

 book, contains as its most valuable features the Patents 

 and Designs Acts in a consolidated form, and a list of 

 the leading cases to which reference has been made 

 in the text. Of lesser value relatively are the reprints 

 of the patents forms, the Patents Rules, and the war 

 legislation, the inclusion of which accounts for the 

 abnormal size of the appendix. These reprints, we 

 think, might very reasonably have been dispensed 

 with as adding unnecessarily to the cost of a very 

 useful book. E. J. 



Technische Traume. Von Hanns Giinther (W. de 

 Haas). Pp. 83. (Zurich: Rascher & Cie, 1922.) 

 50 marks. 



This illustrated pamphlet issued free to subscribers 

 to the journal Natur und Technik contains short 

 accounts of the most important of the proposals which 

 have been made from time to time either to use coal 

 more efficiently in view of its complete exhaustion 

 1500 years hence, or to substitute for it some other 

 source of power. Of schemes falling within the former 

 category the author thinks Ramsay's plan for converting 

 coal into water-gas in situ not likely to prove successful, 

 and attaches more importance to the proposals to 

 generate electric current thermo-electrically or by 

 means of carbon cells. Apart from coal and petroleum, 

 natural power has been derived from sunlight, from the 

 wind, from steam in volcanic regions, from the tides, 

 and from the waves of the sea. Sunlight power plants 

 in tropical regions can, he considers, compete with coal 

 at 105. a ton. while at Landerello in Tuscany all 

 domestic and power heating is supplied by steam from 

 underground heat. The waves have not proved an 

 economical source of power, but the tides are more 

 promising where the necessary structural work is not 



NO. 2/68, VOL. I io] 



too costly. The estimated costs of the Severn Scheme 

 the author thinks too low. 



Filtration: An Elementary Treatise on Industrial 

 Methods and Equipment for the Filtration of Liquids 

 and Gases for those Concerned with Water Supply, 

 Ventilation, and Public Health ; Chemists, Mechanical 

 Engineers, and Others. By T. Roland Wollaston. 

 (Pitman's Technical Primers.) Pp. x+102. (Lon- 

 don : Sir 1. Pitman and Sons, Ltd., 1922.) 2s. 6d. 

 net. 

 The very ambitious title of this small volume would 

 naturally lead one to expect more than is contained 

 in the book. The author has wasted a good deal of 

 the space at his disposal by a rambling style and by 

 irrelevant discussions. Thus, on p. 4 no less than 

 thirteen lines are sacrificed to a reference to a paper in 

 connexion with two very simple chemical equations 

 which are to be found in every text-book. Much of 

 the text deals with very elementary matters, which 

 should be assumed to fie known by the readers. In 

 consequence, the remaining space is insufficient to 

 render possible a clear description, in sufficient detail, 

 of apparatus for technical filtration. 



The Tutorial Chemistry. Part 2, Metals and Physical 



Chemistry. By Dr." G. H. Bailey. Edited by Dr. 



W. Briggs. 12th impression (4th edition). Pp. 



viii + 494. (London: University Tutorial Press, 



Ltd., 1922.) 6s. 6d. 

 Dr. Bailey's text-book, in its revised form, will continue 

 to be useful to students. It gives a clear introductory 

 course of physical chemistry and of the chemistry of 

 the metals. A good feature is the inclusion of brief 

 accounts of the so-called " rare metals," many of which 

 are now technically important. Specific heats at low 

 temperatures might have been mentioned, and we also 

 miss any allusion to Werner's theory and the cyanide 

 process for silver extraction. There are some criticisms 

 which might be made. The definitions in connexion 

 with the phase rule (§ 45) are not sufficiently precise. 

 Stas's silver was not so pure as is implied (§ 281) ; the 

 existence of Mn0 3 is doubtful ; stannous oxide is olive 

 coloured, not black ; and the atomic weight of nitrogen 

 is not a whole number within the limits of experimental 

 error (§ 508). 



Mentally Deficient Children : Their Treatment mid 

 Training. By Dr. G. E. Shuttleworth and Dr. W. A. 

 Potts. Fifth edition. Pp. xviii + 320. (London: 

 H. K. Lewis and Co., Ltd., 1922.) 10s. 6d. net. 

 The fact that a fifth edition of this book has been 

 required is sufficient evidence of its value. It gives 

 in a very comprehensive form a quantity of useful 

 information, legal and medical, concerning the men- 

 tally defective child. At the beginning of the book 

 there is an interesting account of the early efforts of 

 Seguin and other pioneers in this field. This is followed 

 by rhapters on the regulations in England and other 

 countries, the types of mental defect, the treatment 

 available, educational, industrial, and moral training. 

 The appendices supply a list of institutions, both in 

 England and America, where treatment is given, as well 

 as "the medical certificate forms under the Mental 

 Deficiency Act, and a list of the Binet-Simon tests. 

 There is also an excellent bibliography. 



