REVIEWS 167 



work, and to make the qualitative work a subsidiary and more specialised matter, 

 particularly for those who have a leaning towards the analytical rather than the 

 synthetic side of chemistry. 



It is a matter for congratulation, both for Dr. Cumming and Dr. Kay and 

 for the students who use their excellent text-book, that a second edition should 

 have been called for so soon even during the stress of war. The arrangement of 

 the new edition remains unaltered, but the whole book has undergone a careful 

 revision, and one or two new exercises have been introduced. 



Any one who places a copy of this book in the hands of his students may feel 

 assured that if they do not progress it will not be the fault of the text-book. 



As regards the new edition of Treadwell, Prof. Hall reminds us in the Preface 

 to the fourth English Edition that it is no longer to be regarded as a literal 

 translation of the German text, as he has assimilated a good deal also from the 

 text-books of Noyes, Stieglitz and others, "from which many of the ideas 

 introduced into the text have been copied. The general plan of the book has 

 been kept the same, but greater stress has been laid upon the theoretical side 

 of the subject, particularly with regard to the application of the mass-action 

 principle, the ionisation theory, and the theory of oxidation and reduction." 



It is unnecessary to criticise the work further than to say that it is fully up to 

 the standard of previous editions which has made " Treadwell " a household word 

 in the chemical world. 



F. A. Mason. 



A Method for the Identification of Pure Organic Compounds. Vol. II. 

 Containing classified descriptions of about 4,000 of the more important 

 compounds of carbon with the elements of nitrogen, hydrogen, and oxygen. 

 By S. P. Mulliken, Ph.D. [Pp. ix + 327, with 3 illustrations.] (New 

 York : John Wiley & Sons, 1916. Price 21s. net.) 



The syllabuses of many examining bodies require candidates to refer an organic 

 compound to its proper chemical class by a study of its reactions and properties 

 and then by reference to standard text-books or chemical dictionaries to 

 identify the particular compound in hand by means of its physical constants or 

 some characteristic chemical reaction. For examination purposes such an 

 exercise serves as a test of the candidate's systematised chemical mode of 

 thought and of his ability to draw conclusions from his own observations. Once, 

 however, the examination stage of a chemist's life is over, he is on the whole 

 rarely likely to be confronted with the problem of having to identify any known 

 pure organic compound without having the remotest indication of what to look 

 for, and to succeed in such an identification presupposes the possession of a 

 fairly considerable quantity of material. To meet such a case, however, the 

 author has set himself to write a systematic treatise in four volumes embodying a 

 method for the identification of pure organic compounds. Apart altogether from 

 the merits or demerits of the system elaborated, it must be noted at the outset 

 that, as set forth in the sub-title, the book suffers from the grave defect of being 

 incomplete, inasmuch as it contains only those compounds which in the author's 

 opinion are of sufficient importance to deserve inclusion. The " sceptical chemist " 

 will therefore approach the book with a certain lack of confidence lest the 

 particular compound which he is trying to identify is not included within the 

 covers of the book. Such a feeling does not cross the mind of those who are 

 accustomed to refer to such standard works as Beilstein's Handbuch, or Richter's 

 Lexicon, for if the compound whose characteristics are required is known, it may 



