7o6 



NATURE 



[August 5, 1920 



cannot be treated very fully. The information 

 gfiven, however, is accurate, and, whilst the book 

 is readable, it is by no means superficial. Indeed, 

 for a work of its scope it is substantial, and the 

 reviewer has formed a very favourable opinion of 

 it. One of the best sections is the chapter on air, 

 but all are good. A number of examination ques- 

 tions are included. 



(3) Dr. Myers and Mr. Firth's little book has 

 become favourably known as a convenient intro- 

 ductory work on practical chemistry. The ground 

 covered is elementary qualitative and quantitative 

 analysis, including- an outline of simple gas 

 analysis, with methods for making "preparations " 

 and for identifying the commoner organic com- 

 pounds. It gives the requisite information con- 

 cisely, and can be recommended as a suitable 

 initiatory book for medical and pharmaceutical 

 students. 



(4) Messrs. Robertson and Burleigh's book is 

 of a more advanced type than the foregoing. It 

 treats of qualitative analysis only, but aims at 

 giving the student a thoroi/gh grounding m this 

 subject. The authors rightly hold that qualitative 

 chemical analysis, intelligently taught, is of great 

 value in laying a good foundation for a knowledge 

 of the general chemistry of the metals and in 

 illustrating the more important types of chemical 

 reactions. Their method is to familiarise the 

 student with these types (replacement, decomposi- 

 tion, oxidation, and reduction), and thus to enable 

 him to see how they are applied to the problems 

 of systematic analysis. They discard " dry " tests 

 (apart from flame reactions) as being "tedious, 

 often ambiguous, and misleading." They look 

 with disfavour upon the practice of describing in 

 detail, with equations, the individual reactions of 

 the metals. The practice, they contend, is "per- 

 nicious and demoralising " ; and the student, in 

 the end, " simply copies into his notes what he sees 

 in his text-book." It Is by no means clear why 

 this should be so. Surely it Is the part of a 

 capable teacher to find out, by a few suitable 

 questions, whether a student really understands 

 what the equations signify? If this Is done there 

 appears to be no particular objection to describing 

 the Individual reactions, and such a course simpli- 

 fies the work of explanation. But be that as It 

 may, there Is no doubt that the student who works 

 Intelligently through the book under notice should 

 obtain a good grasp of the matter. The questions 

 propounded at the end of the sections will search 

 out his weak points. 



(5) This little book contains Instructions for per- 

 forming a series of simple exercises in physics, 

 chemistry, and bacteriology. As occasion offers, 

 the principles under discussion are applied to, or 



NO. 2649, VOL. 105] 



exemplified by, domestic subjects. Thus, having 

 learned various methods of determining specific 

 gravity, the student uses some of them to find the 

 density of milk. In connection with thermometry 

 she learns how to use a clinical thermometer. In 

 the chemistry exercises she is taught how to make 

 soap, how to remove stains from calico, and so on. 



The exercises are carefully graduated, and, on 

 the whole, are well calculated to stimulate the 

 pupil's interest. Here and there the text needs a 

 little revision. Thus the experiment (3) on p. 45 

 is meaningless as it stands. A weighed quantity 

 of household " blue " Is mixed with water, the 

 mixture evaporated to dryness, and weighed. The 

 student Is then asked to state the percentage of 

 "blue" dissolved! Again (p. 59), permanently 

 " hard " water Is directed to be made by dissolving 

 common salt In distilled water. Then, after the 

 naive remark that " we have used salt because it 

 Is convenient," the pupil is taught how to 

 " soften " (such) permanently hard water by 

 means of washing-soda. These exercises should 

 be revised ; they do not bring out the essential 

 fact that it is the soluble salts of calcium and 

 magnesium, not those of sodium, that cause per- 

 manent hardness. " Of the nitrogenous foods 

 there are protein, water, and salts " (p. 70) is a 

 cryptic saying ; and It is not the only one. The 

 Impression given is that the author occasionally 

 gets a little out of her depth ; but the book as a 

 whole will be found quite useful and convenient. 



(6) At first sight the title "Adds, Alkalis, and 

 Salts " appears rather unattractive — except per- 

 haps to the chemist, who knows these products 

 already. Mr. Adlam, however, manages to make 

 quite a readable little volume on the subject. 

 Many valuable works will, alas ! always and neces- 

 sarily be classed with the "books that are no 

 books," since they must give the dry bones of 

 facts, and no space is available for Investing these 

 facts with even a bare minimum of literary cover- 

 ing. This book, however, alms at being not only 

 instructive, but also interesting. Though starting 

 with little or no knowledge of chemistry, the 

 general reader will have no difficulty In under- 

 standing the text, and will find in it a store of 

 Information concerning the acids and alkalis 

 which Is none the less trustworthy because it Is 

 easily and pleasantly acquired. The book may, 

 in fact, be looked upon as a simple Introduction to 

 the subject of industrial chemistry. Incidentally, 

 it may help to prevent other people following the 

 example of the man mentioned by the author, who 

 took his son to the Royal School of Mines to 

 "learn copper," and not to waste his time over 

 other parts of chemistry, because " they would 

 I be of no use to him." C. S. 



