RECENT BOOKS TEE LAW OF PATENTS FOR CABMISTS. Joseph R o s m n . Ph.D.;

Patent Examiner, U. S. Patent Office; Editor, Journal qf the Potent O&e Society; Chairman, Committee on Patents, etc., American Association for the Advancement of Science. Second edition, The Williams & Wilkins Company, Baltimore, Mary- land, 1934. xi + 378pp. 19.5 X 13.5cm. $4.50.

This book is a revised and improved edition of Dr. Rossman's 1932 treatise on the same subject. In the first edition the an- nounced purpose was t o give a comprehensive treatment of the technical subject of patent law in such a manner that i t could be comprehended by chemists even though they might not have had legal training or legal experience. The present edition, which is an improvement on the first, is a clearly written exposition of the nature of invention and the safeguards which a chemical in- ventor should employ to obtain patent protection for his inven- tion and to reap the benefits of such protection once i t has been obtained. I t covers clearly and succinctly the answers to the thousand and one questions which confront a chemist or a re- search worker whose activities result in new and patentable in- ventions. The explanation of chemical law is amply supported by digests or quotations from leading decisions of the various courts which pass on patent questions. The chemist-inventor will 6nd a wealth of sound advice on how to maintain his re- search records and so order his activities as t o perpetuate his invention and obtain the best patent protection thereon.

Dr. Rossmau has achieved his purpose in a very creditable fashion. for his hook is a condensed, easily readable, and a t the same ti& comprehensive treatment of a very technical sub~ect- that of chemical patent isw. If it can bc criticized it is only for the ~nrnrwhxt too frcauent use of auatatians from court der ihnr - - ~ ~ - - - ~ ~ ~ - - ~ ~~

which. while interestine and instructive to l ave r s , are probably not as instructive to ;he lay-chemist as the .same information would have been if uplained in theauthor'suwn style.

Beyond any doubt Dr. Kos~man'scontribut~an is a valuable one in a field in which there has been all too littlc n-ritine. It has -- - ~~

been the reviewer's experience that even in well-erg-zed re- search departments (where the individual members of the de- partment have become patent-wise) the constructive thought necessary to disclose to a patent attorney a complete invention, includine limitations as to ooeratina conditions and the ranae of eauivaleks necessary to obtain a God patent, forces upon the chemist-inventor a hroader outlouk upon his own invention and the firld of rcsenrch in which he i j active. This naturally rcsulto in stirnulatine further and more effective re*earrh. The hene- f&l effect of&& education as Dr. Rossmau's book disseminates cannot be over-emphasized. EDWARD B. BEALE

MASSANALXSE. TEEORIE UND PRAXIS DER KLASSISMEN UND

DER EL~I 'ROCEE~~~~CEEN TITRIRvERFAHREN. Dr. Gerluwt Jan- der and Dr. Karl Friedrich Jakr, Kaiser-Wilhelm-Institut fiir Physikalische Chemie und Elektrachemie, Berlin-Dahlem. Sammlung Gschen, Walter de Gruyter & Co., Berlin and Leipsig, Germany. 1935. I n two volumes. 277 pp. 42 figs. 10 X 15.5 cm. Each volume RM. 1.62.

The Gschen Collection of hooklets aims eventually to cover the entire field of Science and Arts with brief, up-to-date, readable monographs. The very large number of the hooks that have been published shows that they are meeting a friendly reception. The book at hand, which is printed in two volumes simply because it is nearly twice the standard size, is one of the best that has ap- peared. It is truly remarkable how well the entire field of volumetric analysis has been covered in so little space. At the beginning, a list of twenty-nine standard works is given from which the material has been derived. At the end, a brief history of volumetric analysis is given, starting with the early experi- ments of Descroizilles (1789) and of Vauquelin, with particular reference to Gay-Lussac who can be regarded as the father of volumetric analysis, and with suitable references to the work of

21

Margueritte, Bunsen, Mohr. Volhard, Miiller, Kolthoff, Britton. and others.

The terms used in Volumetric Analysis are defined properly. The instruments are described and the way to calibrate them. The methods start with oxidation-reduction reactions. Eleven typical procedures for work with permanganate are described. including such determinations as those of hydrogen peroxide, uranium. hydroxylamine, manganese in steel, and iron. Under potassium bichromate, four methods are given and the use of diphenylamine as internal indicator is explained clearly, as well as work with the spot plate. Four methods involving potassium bromate are given,fifteen iodometric procedures, and two methods illustrating work with potassium bromate and bromide in acid and in alkaline solutions. The first volume ends abruptly in the midst of the discussion of neutralization reactions. he physical chemistry underlying the titration of weak acids and weak bases is discussed clearlv and simnlv. toeether with the orincioles . .. - . . governing the choice of indicators. In this dijcussiun a few mathematical equations are introduced but in a way that is easy to understand.

In the second volume, ten representative titrations with acids and bases are given including work such as the titration of car- bonates in the presence of hydroxides or of bicarbonates with two endpoints. Under Precipitation Methods, twelve procedures are given including work with the adsorption indicators introduced by Fajans. After this, the theory of conductometric and po- tentiometric titrations is explained and a number of suitable ex- amples of such work are described.

The bwk is well printed and the German is easy to read he- cause it is practically free from the long, highly involved sentences which some German scientists love to use and from the long, com- pound words which cause beginners so much trouble. I t can he recommended to all those who can read German and who wish to review their howledge of volumetric analysis or to find out about such t h i s as pH, oxidation-reduction potentials, or electrometric analvsis. It can be used to advantape bv students who wish to - . rcvicw their howlcdgc prior to some examination and it can also serve for giving studcnts prnctice in reading chemical Gennan. Other bwks in this series have been used fur this last purpoie hut few, if any, of them are as satisfactory. WILLIAM T. HALL

DECEEMA MONO~RAPHIEN. Band 6. Deutsche Gesellschaft fiir Chemisches Apparatewesen. E. V. Verlag Chemie, G. M. B. H., Berlin W. 35, 1934. 128 pp. 9 tables. 98 illustrations. 15 X 23cm. RM. 5 (formembersRM. 4).

The sixth volume of the Dechema Monographs contains eight lectures delivered a t the 1933 meeting of the German Society of Chemical Engineen. The papers included in this volume are mainly devoted to unit operations and materials of construction. Only one deals with industrial reactions, and proposes a classifica- tion of chemical reactions on the basis of states of aggregation. The lectures on unit operations have to do with efficiency of fractionating columns, pressure loss in packed towers, and adsorp- tion of solvents bv active carbon. Those devoted to materials ~~~ ~ ~ *

inrlude high chromium iron alloys, fused silica, tests of welds by a magnrtic-acoustic method, and thc use of X-rays in examination of equipment.

The papers are reasonably comprehensive and thorough, and are mainly of value to the experienced chemical engineer. How- ever, they would serve as excellent parallel reading for advanced students of chemical engineering, not only for their subject matter but for training in reading German. W. T. READ

ROTOBRS UNIYBELUTZ Nsw BnuNswICK, N. J.

DO