448 



NATURE 



[December 24, 1914 



Gibbs, with additional theorems and appHcations 

 developed by the author. Although the book 

 deals with such familiar subjects as chemical 

 equilibrium, the laws of mass action, the phase 

 rule, and osmosis, it does not descend to the 

 discussion of experimental facts, and contains 

 no illustrations of apparatus, no tables of data, 

 and none of the usual ij-raphical representations 

 of equilibria. On the other hand, the mathe- 

 matical treatment of the problems is very 

 thorough and exact. The book will not be 

 likely to attract the average chemist, who prefers 

 to make use of theories only when they can be 

 kept closely in touch with experiment ; but a 

 student who had taken an " honours " degree in 

 mathematics w^ould probably enjoy a course of 

 chemistry in which theory reigns supreme and 

 the limitations of experiment are thrust into the 

 background, or perhaps postponed to a later 

 volume of the series. 



(2) Dr. Gray's "Practical Physical Chemistry" 

 contains a series of thirty-nine exercises, which 

 may be carried out by individual students in 

 periods of two to three hours. It is undoubtedly 

 one of the best books of the kind that has yet 

 been published. The exercises deal with real 

 problems and with real apparatus, in a way that 

 should bring the student into touch with modern 

 methods of exact measurement, and make it easy 

 for him to proceed to original work in physical 

 chemistry if the opportunity should arise. The 

 preliminary discussion on " Accuracy " is particu- 

 larly welcome, and should provide a useful check 

 on the slovenly and inexact measurements which 

 are the chief menace to the success of a course 

 of experimental work in physical chemistry. 



(3) Mr. Jeffery's "Notes" are a series of sum- 

 maries of the data that are necessary for answer- 

 ing ten of the questions that are most commonly 

 set in examinations on chemistry, e.g. on acids, 

 salts and bases, oxides, oxidation and reduction, 

 electrolysis, etc. To the student preparing for 

 examinations the advantage of having these data 

 in a compact form will be obvious, though he 

 might well expect to find most of the informa- 

 tion in a general text-book. The compilation has 

 been done carefully, and criticism may be con- 

 fined to points of detail. Thus, it is curious to 

 find no reference at all to the sour taste by which 

 acids first acquired their reputation, although their 

 action on litmus and their electrolytic properties 

 are described ; the reader is also not told whether 

 the solubility of metallic hydroxides in caustic 

 alkalies brings them within the category of acids 

 or not. It is, however, satisfactory to find that 

 the author has realised the difficulty of defining 

 acids, salts, and bases, and is for the most part 



NO. 2356, VOL. QJlI 



content with describing their characteristic pro- 

 perties ; such a description might well be made 

 into a historical statement showing the gradual 

 development of the idea of an "acid" in the 

 hands of Lavoisier, Berthollet, Gay Lussac, and 

 Laurent, and of a " salt " in the hands of Boyle, 

 Lavoisier, Berzelius, Laurent, and others. In 

 dealing with students, it is a pity to allow them 

 to "obtain " common salt by mixing caustic soda 

 and hydrochloric acid, and to regard this as a 

 "preparation" of the salt; an exercise on the re- 

 crystallisation of rock salt or the extr.action of 

 common salt (and Epsom salts) from sea-water 

 would be of greater value, and much more in 

 touch with reality. 



(4) Mr. Bassett's book is intended for medical 

 and dental students who require to obtain within 

 the course of a single year some knowledge both 

 of inorganic and of organic chemistry. The 

 requirements of such a syllabus are in no way 

 incompatible with a sound scheme of instruction ; 

 the study of alcohol, for example, affords excel- 

 lent material for explaining methods of purifica- 

 tion, tests of purity, and the fundamental prin- 

 ciples of analysis in a course of general chemistry. 

 Roscoe's "Lessons" may be quoted as a very 

 successful example of a combined course of in- 

 organic and organic chemistry ; but the medical 

 student of the present day has been somewhat 

 badly served In the matter of text-books, and Mr. 

 Bassett's book is an attempt to fill a gap that is 

 recognised clearly by those who are responsible 

 for the teaching of medical and dental students. 



In spite of certain merits that the book pos- 

 sesses, it is doubtful whether it will secure any 

 extensive foothold in the medical schools. Actual 

 experience shows that it is a mistake to discuss 

 the periodic classification of the elements before 

 any of them have been studied in detail. More- 

 over, this classification is not a suitable basis 

 for an introductory study of the elements. The 

 author has boldly adopted it, and described the 

 elements in the order in which they occur in 

 Mendeleeff's table. He therefore postpones the 

 consideration of oxygen and chlorine until all the 

 metals, except those of the iron-group, have been 

 described. Here again, as experience shows, he 

 has made a fatal mistake, and not one student in 

 a hundred is likely to benefit by using the scheme 

 which the author has adopted. 



Whilst most of his statements are accurate, the 

 author has admitted several errors, from which 

 the student might reasonably expect to be pro- 

 tected. He would be unwise, for example, to 

 assert with the author that barium monoxide is. 

 prepared by heating the carbonate, or that in a 

 combustion oxygen is draivn through the ap- 



