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281 



THURSDAY, JUNE 7, 1917. 



BOOKS ON CHEMISTRY. 

 (i) Elementary Qualitative Analysis: A Labora- 

 tory Guide. By Prof. B. Dales and Dr. O. L. 

 Barnebey. Pp. vii + 205. (New York : John 

 Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd., 1916.) Price 55. 6d. net. 



(2) Laboratory Manual of General Chemistry, with 

 Exercises in the Preparation of Inorganic Sub- 

 stances. By A. B. Lamb. Pp. vi+i66. (Cam- 

 bridge, Mass. : Harvard University Press, 

 1916.) Price 1.45 dollars. 



(3) A Text-book of Organic Chemistry for 

 Students of Medicine and Biology. By Prof. 

 E. V. McCollum. Pp. xiii + 426. (New 

 York : The Macmillan Co. ; London : Macmil- 

 lan and Co., Ltd., 1916.) Price 10s. net. 



(i) A LTHOUGH the value of instruction in 

 ■^*- qualitative analysis is far more de- 

 pendent upon the teacher than upon the text- 

 books provided for the students' giiidance, much 

 useful assistance is to be gained from the latter 

 if they are based upon a sound method of experi- 

 ment and observation. From this point of view 

 the "Laboratory Guide to Elementary Qualitative 

 Analysis " by Prof. Dales and Dr. Barnebey 

 inerits the attention of teachers in this country. 

 The book is designed for the use of students who 

 have done a year's work in general chemistry. 

 The principles of qualitative analysis as based 

 upon the theory of electrolytic dissociation are 

 dealt with in an introductory chapter, which 

 should prove, helpful to students in bringing their 

 experimental work into line with their training in 

 general chemistry. An outstanding feature of 

 the details of qualitative analysis is that the re- 

 actions of the several groups of bases and acids 

 are studied comparatively with each of the re- 

 agents employed, instead of by the more usual 

 ;nethod in which the tests for each base or acid 

 are dealt with separately. This method of treat- 

 ment has distinct advantages, esp>ecially as a 

 training in the methods of observation. The 

 group-tables for bases are similar to those usually 

 employed, but the scheme for the detection of 

 acids is somewhat new and is based ujx)n the 

 precipitation of the silver salts in distinctly acid 

 and in neutral or slightly acid solution respec- 

 tively. The instructions are clear, concise ex- 

 planatory statements add considerably to their 

 value, and the purpose of qualitative analysis as 

 a basis for the further practical study of chemistry 

 is very satisfactorily explained. 



(2) The object of Prof. Lamb's "Laboratory 

 Manual of General Chemistry " is to widen the 

 horizon of study of first-year university students 

 who have had a previous training in chemistry 

 at a secondary school, and at the same time to 

 stimulate their further interest in important 

 generalisations of the science by means of experi- 

 ments of a less familiar kind than those with 

 which they have been previously acquainted. 

 With these aims in view a number 6f quantitative 

 experiments are described requiring varying de- 

 XO. 2484, VOL. Qol 



grees of previous knowledge and experimental 

 skill, together with a series of semi-quantitative 

 experiments in the more elementary portions of 

 physical chemistry. The directions for each ex- 

 periment comprise suggested reading from some 

 standard text-book, a discussion of the general 

 principles involved in the experiment, directions 

 for the actual manipulation, tests and questions. 

 Appended to each of the instructions is a blank 

 sheet for laboratory notes ; these are to serve as 

 the basis for a full and connected account of the 

 work done, which is afterwards to be written up. 



Such attempts to combine instruction in theory 

 with details erf experiment and series of questions 

 in a laboratory text-book are seldom satisfactory' 

 in actual practice. They are apt to stereotype 

 the teaching, to take too little account of the in- 

 dividual difficulties of students, and to absolve 

 the teacher of his real responsibilities. The selec- 

 tion of the experiments and preparations is tor 

 the most part sufficiently wide to provide a useful 

 curriculum, but the descriptive headings and dis- 

 cussions are in many cases considerably more 

 advanced than the actual laboratory exj>eriments. 

 Also., a number of the exercises, such as the 

 determination of the electrical conductivity of a 

 isolution, the preparation of hydrazine sulphate and 

 of chJoropentamine cobaltic chloride, are much 

 beyond the knowledge and manipulative capacity 

 of an average first-year student in this country. 



(3) The importance of organic chemistry to 

 students of- medicine and biology fully justifies the 

 publication of an additional text-book if it serves 

 their special requirements satisfactorily and stimu- 

 lates their interest in the subject. These objects 

 are ver\' successfully achieved by Prof. McCol- 

 lum 's book. The subject-matter is presented in 

 a clear and attractive form, the sequence of the 

 comf>ouhds described is chosen with care and 

 with an advantageous departure from the usual 

 order, and suitable prominence is eiven to the 

 methods of preparation, properties, and syn- 

 thetical relations of substances of biological and 

 physiological importance. Details in regard to 

 laboratory and technical processes are intention- 

 ally restricted. Whilst this is not necessarily dis- 

 advantageous, the danger of introducing "paper 

 chemistry " is not altogether avoided, as in the 

 scheme of oxidation of alcohol to oxalic acid (p. 

 201), in which the stages of oxidation represented 

 are not in accord with experimental methods. 



Theoretical studies such as stereochemistry are 

 developed as individual compounds come under 

 consideration, a method of treatment which should 

 appeal to the interest of students, although it 

 necessitates a considerable use of cross-references. 

 The prominence given to Nef's views on divalent 

 carbon is somewhat out of proportion to the space 

 allotted to other and more fully established views 

 on the structure of organic compounds. Refer- 

 ences to recent work are very suitably introduced, 

 and the more special chapters included in the 

 book, such as those on fats and waxes, the 

 ureides, the pyrimidines, pyrazines, and purins, 

 and the carbohydrates, are well adapted to their 

 purpose. C. A. K. 







