This book is designed primarily to accompany an7 of the more recent text-books onsenera1 =hem-
istry. Part I1 has been added for-by 6r.tyear college students, and in t h o r high schools where courses in qualitative and quantitative analysis are offered:' The material in this book is divided under three main heads, as follows. Part I. Type Probl",,s. I n this part ten types are pre-ented. ~ u c h for , example, as "Valence and the Writing of Formulae: ''Gases and Their Measurement," "Equivalent Weights:' ete. In each e a r , the law or type is first defined and an example or two is solved. Follo+ng this is a 8et of problems of the same type. Near the end of this section is a r t of miscellaneous ererdaes, and, finally, a list of problemn taken from the New York State Regents Examination Papers, 1915-1926. Part 11. Problems f a FirsCYcar Collcnr 31%. dcnls. These problems cover such topics as "Moleedar Weights," "Paraday's Laws" "Atomic Weight.," "Volumetric Analysi.:' '.Gravimetric Analysis," and are of a little more difficult type than tho= of Part I. Part 111. Prablcmr Based on Lerron Assignman,s. I" this section the page. are divided. At the top of each page are given type equations covering the usual topier in the usual order, and a t the bottom are presented problems involving these equations. At the end, the book containr Appendices, such. lor example, as ".\rornie Wriahlr," "Convcc4un Tahles " ' Dcnritv 01 Aeirln.""Soeci5e Hcau."crc . . The problemsare in general well-stated and well-, graded to c m s p o n d t o the studento' ability. The only weakness, as the reviewer sees it, is in the definitions. The author shares with the rent of us the uncertainty about the true nature of valence. I t is defined. variously, as "the eapacity to unite," the "power to repbee," or as a number, c. g., "three." Gay-Lusrae'r Law of Volumes is defined thus: "The rrlolivc eombiniog volumes of eases. . . or the volumes of their oroducts. if gaseous, can be expressed in a ratio of m a l l whole number^." Why not leave out the words "a ratio of," The word "relative" shove implies the same thing. The G, M, ". is given e ,,22,2," molar solution is one containing the pram-molecdar of the in loOo raluenl,"
,.*
while in normal solution we have "1000 rc. of This makee the molar solution useles in work, and it mluliov:'
to tran.1ate "molar" into .'normal such slips have
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no doubt, be corrected in a mvidon, This little volumesho,,ldeertainly find a placein every high. school library, and i t also presents something of a to the of fimt-year college chemistry.
W, H, CRAP,N
Graded Exercises in Chemistv. M m n w MBNneb. Globe B w k Company. New York, 1926.
196 pp. $0.53.
19 X 13 em.
Reavy paper cover.
This book contains 28 chaptas of well-selected and clearly stated questions suited to high-school students. Their titles correspond in svhstanee to the titles of the chapters in any high-xhaal chemistry text-book and each chapter is a unit directly related to its subjects. The chaptus on formulas, nomenclature, types of ehemieal equations, and chemical arithmetic are accompanied by brief explanations which will be welmmed as clear lights on subjects urually dark to high-school pupils. There chapters are followed by ten specimen examioationn in which five groups of three quentionr each are given from which the pupil is to select ten questions, including a t least one quention from each gmup. These quwtion:, have a wide range,assume a thorough acquaintance with the Brrt 28 chapters of the book and will test the ability of the student to relate chemistry to everyday life. The b o d closer with fovr tables ol important phytieal constants. The reviewer believe. that this book ir an ercellent representation of the system of teaching in which a c m r s e is built around questions and that it could be used with any good high-school text. But he a1.o believes that while this system may be an antidote for "haphazard study" it may, if relied on entirely, become an antidote for the valuable system in which a first-ei.ss teacher by f ~ c s hquestions seeks not only t o train the pupil's ability t o distinguish between the important and the less important but also to direct his attention to the very latent developme+= in the field of chemistry. By a teacher of this kind the b w k may be used as a basis of review, to a less experienced teacher it may be of great value as a n ~ c l e u saround which to build a murse. L O ~ W. S M~trsnn EinfUhmng in die physlkalische Chemie und Kolloidchemie. H. R. K ~ u u r . Akademirehe Verlagrgcrellrchaft. Leiprig, 1926. xiii 208 pp. 14.5 X 21.5 em. M. 10.
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The author states in the preface that this volume is intended to give the students of medicine and the biological sciences an inoight into the principles of physical and c o h i d cbemi3try. I t is the belief of the reviewer that he has admirably It a real and % s w r i a e t o 5nd so mu& exact information condenscd within these few pages. I n a dear and simple ~ t y l the c author elucidates the fundamental principles underlying the gas taws, diffusion, osmosis and osmotic pressure. weight detuminationn' rates Of reactions, eatalyes and autocatal~tie reactions. ehemieal equilibria and rraetionr in heterogeneous systems, the theories of ionization and eleetrolytie die.aeiation, ion concentration including a di.. cmsdon of electrometrie methods, indicators and buffers, solvbility products, surface tendon.
