;i8 



KNOWLEDGE & SCIENTIFIC NEWS. 



[August, 1906. 



CHEMISTRY. 



Joseph I'riestley, by T. E. Thorpe, F.R.S. ; pp. ix and 22S. 

 English Men of Science Series (Dent and Co.) — The work 

 of the chemist does not " touch life," to use an .\mericanism, 

 at many points, and so the world has not had its intere.'t 

 awakened in the lives of many of those who helped to build 

 up chemistry into a science. Thus, if you ask an average 

 Englishman what he knows about Priestley, he will pro- 

 bably tell you that he had .something to do with the discovery 

 of gases, and that his house was burned in the riot at 

 Kirmingham ; but of the man himself, or of his surround 

 ings, he will know nothing. We, therefore, owe a debt 

 to Dr. Thorpe for giving us in an accessible and very read- 

 able form a life of Priestley which, though of necessity 

 too brief, yet brings the man and his time vividly before 

 us. The account, which is to a large extent based on 

 autobiographical notes, gives us incidentally a succession of 

 pictures of middle-class life in the latter half of the i8th 

 I cntury. \\'e follow Priestley through his boyhood among 

 the handloom weavers in Yorkshire, his training for the 

 dissenting ministry, his struggles as a minister, " passing 

 rich on forty pounds a year " (a large amount of which 

 he did not get), his more successful venture as a private 

 schoolmaster, and his appointment in the Warrington 

 Academy, where his scientific career may be said to have 

 begun. Then come his marriage, his association with 

 Lord Shelburne, his life in Birmingham, where he 

 became a prominent member of the Lunar Society, the 

 violent attacks made upon him from all sides at the height 

 of his scientific career, on account of his supposed sympathv 

 with the French revolutionists, his virtual banishment from 

 England, and his settling and death in America. Dr. 

 Thorpe has dealt with all these chapters of Priestley's life 

 •-•cncisely, but yet sympathetically, and with sufficient detail 

 to give a clear idea of the man, strong, and ever struggling 

 against circumstances to express what he believed to be the 

 truth, both in religion and in science. The last chapter, 

 dealing with the chemical work of Priestley, is, perhaps, 

 somewhat too abstruse for the general reader, but it will 

 be read with the greatest interest by the chemist, for Dr. 

 Thorpe brings out clearly how often Priestley was on the 

 very verge of great discoveries, which he missed solely 

 thiough his reluctance to part with the old doctrine of 

 l-hlogiston. As Dr. Thorpe remarks : " Priestley was ni 

 fact a pioneer ; he showed the existence of a new world for 

 .science, and he himself roamed over a portion of it, like 

 a second Joshua ; but he had not the experience or the 

 aptitude to map out accurately even that fraction." 



Chemistry Lecture Notes, by G. E. Welch, B.Sc. 

 (London : Blackie and Son ; pp. 63, is. 6d.) — The notes 

 given in this little book are such as should be taken by 

 students working; at stage II. of Inorganic Chemistry. 

 They are clear and concise, and should be of use in gomg 

 over the ground before an examination. Yet, in spite of 

 the author's remark in the preface, that " Much valuable 

 time is wasted in note-taking," we cannot help thinking 

 that the stained notes of the student, written down in his 

 own words at the time of the experiment, are of infinitely 

 more value as a training in chemistry than mastering these 

 model notes, which he can assimilate for examination pur- 

 poses and then forget. 



GEOMETRY 



Geometry, Theoretical and Practical, bv W. P. Workman. 

 M.A., B.Sc , and A. G. Cracknell, M'.A., B.Sc, F.C.P., 

 price 3s.6d. If the University Tutorial Pressisguilty of produc- 

 ing a further addition to the already overflowing list of ■' Geo- 

 metries "_ recently brought out " to meet modern require- 

 ments," it cannot be said that the addition is in any way 

 unjustifiable. Since the bygone days, when a small' circle 

 of authors commenced to write books for the then new and 

 practically unknown series, a noticeable feature of these 

 books has been the absence of mere repetition of methods, 

 good, bad and indi.fferent, contained in previous text-books, 

 and those who are behind the scenes know that in many 

 instances, the improvements which have seen the light in 

 these books have only been effected by considerable expendi- 

 ture of time and money. The new Geometry contains 

 abundant evidence that the authors have succeeded in im- 



pressing their own individuality on even this well-worn 

 subject by the introduction of many desirable and novel 

 features ; indeed, under the circumstances, the book strikes 

 us as one of noticeable originality. It commences with an 

 introductory course in constructive Geometry not only of 

 plane figures, but of the simple solids, and throughout the 

 remainder of the book a careful balance has been maintained 

 between theoretical deductions, constructive exercises, exer- 

 cises solved by calculation, and riders. We do not alto- 

 gether agree with the arguments for abolishing Euclid 

 contained in the preface, and we believe that the real facts 

 of the case ar^ but little understood. So far as order of 

 treatment, and so forth, is concerned, the Geometry of the 

 present day is not new; the "Text Book of Science," by 

 Watson, published considerably over a quarter of a century 

 ago, being identical with it even in many such points of 

 detail as the admission of " hypothetical constructions." 

 But if W'atson had lived in the lime of Euclid and Euclid 

 had lived in the time of Watson, a change from " Wat- 

 sonian " to " Euclidian " methods might equally well have 

 been heralded as a reform. Where the real improvement 

 comes in is in furnishing Geometry with " examples," 

 similar in point of relative difficulty to the examples by 

 which beginners learn arithmetic and algebra. It is re- 

 markable that while, as the authors say, " the Euclidian 

 methods of the year igoo represented the accumulated ex- 

 perience of many generations of competent teachers," these 

 teachers had never devised any plan of teaching otherwise 

 than by making their pupils either learn up the proposi- 

 tions or putting them on to solve hard riders which many 

 of them never could solve, .and which the teacher himself 

 had in most cases to solve for them. The introduction of 

 the ruler, compasses, and protractor has now supplied 

 beginners with plenty of examples which they can work out 

 for ihemseft'es, and learn something in working them. We 

 are glad to see that the chapter on loci contains an exercise 

 on plotting an ellipse, and that in connection with " hypo- 

 thetical constructions " the reader is warned against the 

 mistake, of which " join O to P bisecting the angle A O B " 

 is a common instance. 



NATURAL HISTORY. 



Recreations of a Naturalist. By J. E. Harting. (London: 

 T. Fisher Unwin, 1906, pp. xvi. + 233, illustrated; price 

 15s. net). — Mr. Harting is such an old favourite with the 

 nature-loving public that any work from his pen is almost 

 sure of a favourable reception. He has, moreover, the ad- 

 vantage of being not only a first-rate field naturalist, but 

 likewise an ardent sportsman, and also, to some extent, an 

 antiquarian, having a very large acquaintance with early 

 English and foreign literature. He, therefore, appeals to 

 a much wider field than that with which the majority of 

 writers on popular natural history are obliged to be content. 

 The articles in the volume before us have already appeared 

 in the Field (without, in most instances, the illustrations, 

 which add to their attractiveness), and the author has ac- 

 cordingly had the opportunity of revising his views when 

 necessary. They cover such a wide range of subjects as 

 hawking, grouse and black-cock shooting, distribution of 

 partridges, origin of the cat, sheep-dog trials, bird life on 

 the Norfolk Broads, swan-upping on the Thames, and the 

 oldest work on angling. To be an expert on such a 

 diversity of subjects alone proclaims great capacity and 

 industry, and if the author is a little less up-to-date in some 

 of the articles, such as the one on the ancestry of the cat, 

 he may v/ell be excused. We have read the book with 

 pleasure, and can heartily commend it to our subscribers. 



PHOTOGRAPHY. 



Successful Negative Making, bv T. Thome Baker, F.C.S., 

 F.R.P.S. (London : Marshall, I^rookos and Chalkley, Ltd. ; 

 price 6d.) — This, the first of the " Focus Photographic 

 Manuals," is a small volume of forty-one pages divided into 

 five chapters, dealing with the plate, exposure, develop- 

 ment, fixing, washing, intensification, and reduction. Some 

 of the statements in the book are not orthodox, as, for 

 example, that a colour screen is less needed when the colours 

 are brilliant and " rich " than where there is a great deal of 

 reflected white light, and that, in general, the colour screen 

 or filter must be suited to the view; that " for lantern slide 

 making one wants really harsh negatives to get the best 



