280 



SCIENCE. 



[N. S. Vol. V. No. Ill, 



based upon the best sources and made with 

 great care. The chapter adds much to the value 

 -of this volume as a book of reference. 



Alexander Ziwet. 

 University of Michigan. 



The Development of the Periodic Law. By F. P. 



Venable, Ph. D., Professor in the Univer- 



versity of North Carolina. Easton, Pa., 



Chemical Publishing Company. 1896. Pp. 



viii+321. Price, $2.50. 



The purpose of this book cannot be better 

 given than in the author's own words : "This 

 work * * * is to be used for purposes of refer- 

 ence and of study, and not as a mere history of 

 the subject. The errors and repetitions of the 

 writers upon this subject in the past few years 

 have abundantly proved the necessity for some 

 such gathering and systematizing the work of 

 former years." 



Professor Venable' s work iu writing his re- 

 cently published History of Chemistry has given 

 him an excellent preparation for the critical 

 study of the discovery and development of the 

 periodic law, which is given in this volume. As 

 stated by the author, much of the literature of 

 the subject is in hidden and out-of-the-way 

 places and a very real service is rendered to 

 chemical science in thus coordinating it and 

 making it more easily accessible. The scope of 

 the book includes an account of the numerous 

 attempts which have been made to discover 

 numerical and other relations between the 

 atomic weights and also an account of specula- 

 tions as to the origin of the elements and their 

 relation to some fundamental form of matter. 



Calculations and speculations of this kind 

 have had a fatal fascination for a great many 

 chemists, and as we look over the literature and 

 see how much has been written that is fanciful, 

 and how much that in the light of better knowl- 

 edge has been found erroneous and worthless, 

 we are almost tempted to turn from the whole 

 subject in disgust. And there is no doubt that 

 many of these speculations have been worthless 

 and the time of their authors has been nearly 

 or quite wasted, for they have led to no ac- 

 cepted conclusions and they have given no in- 

 centive to useful work. But the periodic sys- 

 tem stands on quite a different plane, for it 



furnishes us the best means at present available 

 for coordinating our knowledge of the chemical 

 elements, and it has furnished the incentive for 

 a large amount of most excellent experimental 

 work. That there are some imperfections in 

 the system and that it does not, at present, give 

 any accurate mathematical expression for our 

 chemical knowledge must be admitted. It is 

 tantalizing in its suggestiveness, and most chem- 

 ists believe that it half reveals facts which will 

 be of profound importance when fully under- 

 stood. If the present work turns the attention 

 of chemists in that direction it may prove very 

 useful. 



A quite full bibliography and an excellent 

 index add to the usefulness of the work. 



W. A. N. 



Notes on Qualitative Analysis, arranged for the 

 use of students of the Rensselaer Polytechnic 

 Institute. By W. P. Mason, Professor of 

 Chemistry. Third Edition. Easton, Pa., 

 Chemical Publishing Company. 1896. Pp. 

 56. Price, 80 cents. 



This book gives a concise statement of the 

 more important qualitative tests for metals and 

 acids, those for the metals being arranged in the 

 order of Fresenius. Then follow tables for an- 

 alysis of metals, and five pages giving very 

 short directions for the analysis of alloys, in- 

 soluble substances and alkaline solutions. 



The selection of tests is satisfactory and the 

 book will, doubtless, furnish a basis for a good 

 short course in the subject. It would seem, 

 however, that even au elementary work should 

 give directions which are reliable for cases of 

 very common occurrence. For instance, am- 

 monia often fails to separate small quantities of 

 silver chloride from mercurous chloride ; and 

 ammonia will not separate zinc from chromium 

 unless the zinc is in excess. Neither case is 

 provided for in the directions given. 



Books of this character may furnish students 

 with excellent drill in scientific methods of 

 work and, in the hands of a good teacher, are 

 satisfactory from that standpoint, but the stu- 

 dent should understand that he is liable to fall 

 iuto very serious mistakes if he attempts to use 

 the directions for practical work. 



The references to Watts' dictionary and the 



