May II, 191 1] 



NATURE 



345 



portant chapter deals with "carrier" cases, and con- 

 jlderable stress is laid on this mode of the spread of 

 infective diseases. The limitations to the value of 

 isolation for the prevention of the spread of infectious 

 diseases are criticall}' discussed, and the conclusion is 

 reached that isolation is of far less value than was 

 formerly believed. Bacterial and protozoal diseases 

 are both dealt with, and full references are given to 

 the literature. 



R. T. H. 



CHEMISTRY FOR MATRICULATION. 

 (i) A Class-Book of Chemistry. By G. C. Donington. 

 Pp. xi + 399. (London : Macmillan and Co., Ltd., 

 191 1.) Price 3s. 6d. 

 (2) Chemistry for Matriculation. By Dr. G. H. 

 Bailey and H. W. Bausor, Pp. viii + S48. (Lon- 

 don : W. B. Clive, 1910.) Price 5^. 6d. 

 '(l)lV/fR. DONINGTON'S volume is a very in- 

 i-'J- teresting attempt to combine a practical 

 course on modern lines with a descriptive text-book. 

 The arrangement of the matter is distinctly original 

 and has been carefully thought out. Discussion of 

 more abstract topics, such as the atomic theory, 

 Avogadro's hypothesis and valency, is postponed to 

 a late stage in the book, while no chemical formula 

 appears' until p. 283. The preference thus given to a 

 more descriptive treatment of the science is all to the 

 good in an introductory class-book of this kind. In 

 the early chapters the author deals very appropriately 

 with the physical operations and physical properties 

 which are used in the purification and characterisation 

 of individual substances, such as solution, crystallisa- 

 tion, distillation, determination of melting points and 

 boiling points, measurement of volume and density 

 of gases. The first topics of a definitely chemical 

 nature to which the reader is introduced are " acids 

 and alkalis," "neutralisation," "rusting" and 

 "burning," "active and inactive constituents of air," 

 "elements and compounds." It must not be sup- 

 posed that this descriptive treatment involves the 

 suppression of the quantitative aspect of chemical 

 chanees. On the contrary, the author contrives in 

 the earlier part of the volume to introduce the pupil 

 by the way to the fundamental quantitative facts of 

 chemistrv. 



While the general arrangement of the subject- 

 matter is excellent, it may be doubted whether the 

 author attains his object of providing a basis for 

 teaching by research methods. With this in view, 

 each topic is, as far as possible, introduced by the 

 suggestion of experiments to be carried out by the 

 pupil, these leading up to the solution of various 

 problems. The paragraphs, however, in which 

 appropriate experiments are indicated are followed by 

 an authoritative description of all the facts bearing 

 on the question. Various experiments, for instance, 

 relative to the nature and cause of iron rusting are 

 su^^^estcd, and the results obtained are supposed to 

 enable the pupil to answer such questions as " Does 

 Iron rust in dry air?" "Does water only cause iron 

 to rust?" "Is the rusting of iron a chemical or a 

 physical change?" The correct answers, however, 

 NO. 2167, VOL. 86] 



are supplied in the descriptive paragraphs which 

 follow, and it is plain that the replies given by the 

 pupil under such conditions cannot be unprejudiced. 



The selection of practical exercises is excellent, and 

 the course has stood the test of actual experience. 

 The illustrations include portraits of such pioneers 

 as Priestley, Lavoisier, Davy, and Faraday. 



A curious error is the spelling of Avogadro's name 

 throughout as Avagadro. 



(2) The second volume under review belongs to the 

 "University Tutorial Series," and is based on Dr. 

 Bailey's earlier work, "The New Matriculation 

 Chemistry." The authors aim at a tvrmbination of 

 the heuristic and didactic methods of teaching, and 

 practical exercises for the pupil are accordingly inter- 

 woven with the text. 



The book begins with an introductory course in 

 which " special care has been devoted to the treat- 

 ment of the Laws of Constant and Multiple Propor- 

 tions, Avogadro's Hypothesis, and the meaning and 

 use of Chemical Formulae and Equations." There is 

 much, however, in the discussion of these topics that 

 is open to criticism. Thus, for instance, Avogadro's 

 hypothesis is described on p. 141 as a •'law," the 

 word molecule is used in different senses without any 

 explanation, atomic weights are tabulated and used 

 before the idea of "equivalents" is introduced, and 

 hydrogen is taken as the standard of atomic weights. 

 According to the preface, the book aims at providing 

 a course of fairly detailed study in chemistry, and 

 yet no information is given as to practical methods 

 of deducing atomic weights from equivalents; there 

 is, for instance, no reference to Dulon^ and Petit's 

 law. 



The choice of practical exercises to be performed 

 by the student is not always wise. Dropping a piece 

 of sodium about the size of a pea into water, and 

 demonstrating the low ignition point of benzoline, are 

 experiments which in the hands of beginners might 

 have unpleasant consequences, while such exercises 

 as the preparation of ethylene and the conversion of 

 yellow phosphorus into the red variety are not suit- 

 able for the matriculation student. 



J. C. P. 



OUR BOOK SHELF. 



Tratiato di Chimica Inorganica gciierale e applicata 

 all' Inditstria. By Prof, E. Molinari. Terza 

 edizione. Pp. xvii4-924. (Milano: U. Hoepli, 

 191 1.) Price 16 lire. 

 When the first editior^ of this work appeared in 1905 

 its manv excellent and novel features were commended 

 in the full review which was' published in Nature 

 of February 29 of that year. That these qualities 

 were widely appreciated is shown by the fact that a 

 second edition was called for within a year, and a 

 third edition is now being issued. The present edition 

 contains a very large amount of new matter, above 

 200 pages having been added to the text, fifty-six 

 of which belong to the general introductory sectipn, 

 and deal with such subjects as mass-action, equili- 

 brium, dissociation, and the phase rule. That the 

 revision of the special section has kept pace with the 

 march of modern industrial development is shown bv 

 the very thorough alterations which have been made 



