November 1, 1900.] 



KNOWLEDGE. 



257 



researches on the Wolf-Rayet Stars, the study of whicli they have 

 followed with such consincuous thoroughness. 



" iNTRonriTiox TO Zoology. A Guide to the Study of 

 Animals, for the use of Secondary Schools." By (". B. and 

 G. C. Davfnport. (The JJacmillan Comiiany.) Illustrated. 

 Price (js. Unlike naany works in popular natur.al history, in 

 this excelKnt little volume the greater I'ortion of the text is 

 devoted to the invertel rates, the vertebrates receivin;;; only 

 that amount of space to which they are entitled by " propor- 

 tionate representation." The contents of the second chapter 

 (.taken at haphazard), which treats of the butterfly and its allies, 

 will serve as an example of the mtihod followed in other 

 groups. Firstly, we have the systematic position and 

 characteristics "of these insects concisely but adequately 

 explained. This is followed by an account of their liabits, 

 which is in turn succeeded by a di!-cour.«c on the different 

 sexual features and the phenouieuon of polymorphism. Next 

 we find a capital dissertation on mimicry and protective 

 resemblances, followed by a brief account of the different 

 families of butterflies and moths. This naturally leads on to 

 the consideration of the other great order of four-winged insects 

 — the HjTnenoptera — and the chapter closes with a cleverly 

 drawn-up "key ' to the identification of the various families of 

 the two orders in question. Where we have tested these 

 ■' keys," as we have done in the case of the vertebrates, we find 

 them in the main very s-atisf-actory, although we must protest 

 against the definition '' without hands" which is. used in the 

 case of the carnivora and rodents, for surely the fore-paws of a 

 squirrel subserve almost all the uses of those appendages. The 

 style in which the work is written is as attractive as the brevitj' 

 of treatment admits, and we are glad to note that economic 

 zoology comes in for a fair share of attention. Neither are 

 extinct forms altogether omitted, mention being made, as 

 occasion requires, of some of the more important groups. It 

 scarcely, however, gives a true conception of the fact to allude 

 to the various orders of extinct reptiles as if they were merely 

 families of the Lacertilia. AU the illustrations are good, and 

 many of them excellent ; the reproductions from photographs 

 of living fish by Dr. Shufeldt being a new feature worthy the 

 best attention of all naturalists. The artistic grouping of 

 animals in fac-similes of their natural environment, as in the case 

 of the black -Uaskan sheep, is also to be commended. When it is 

 added that laboratory work forms an important item in the 

 contents of this admirable little volume, we think we have said 

 enough to commend it to the best attention of our readers, 

 whether juvenile or otherwise. 



"The Letters of Jijss Jakob Berzelius .wd CHRISTI.^^■ 

 Friedrich SliimNEeix, 1830-1847." Edited by Georg W. A. 

 Kahlbaum. Translated by F. V. Darbishire and N. V. 

 Sidgwick. (Williams and Xorgate.) 3s. We have already 

 called attention this year to the letters of Faraday and 

 Schonbein, which were published under the same able editorship 

 as those now before us. Schr.nbein, as early as 1827, had 

 spoken of Berzelius as one of the leading lights of the age 

 among chemists. He had, indeed, made unsuccessful efforts 

 with London publishers to arrange to translate Berzelius' 

 Ldrhoh i Kem icn into English, a disap])ointment which prevented 

 Schonbein, as he said, not only from benefiting British chemists, 

 but also from raising sufficient money to take him to Stockholm 

 to cf)nclude his studies under " the consummate master of 

 chemical science." In 1828, Schimbein was appointed to his 

 professorship at Bale, from which place eight years later he 

 began his correspondence with Berzelius. The first of the 

 fourteen letters of Schonbein's included in this volume was 

 despatched from Bale on the 22nd April, 183G, and contains an 

 account of his experiments on the action of nitric acid on iron ; 

 but no answer was received from Berzelius until 4th May, 18.j7, 

 when he wrote giving his views on the " passive " state of iron, 

 and expressing the hope that the search would be continued. 

 SchMnbein's last letter to Stockholm is dated 29th March, 1847, 

 so that intervals of about twelve months elapsed between the 

 different letters. The characteristics to which we directed 

 attention when dealing with the correspondence of the Bale 

 professor with Faraday are here also very noticeable. SchiJnbein 

 was always anxious to obtain the 0])iuions of contemporary men 

 of science upon the conclusions he drew from his researches, 

 and ever willing, if he saw sufficient reaiion, to modify his views. 



There is, however, an absence of those expressions of cordial 

 friendliness which were so marked and pleasing an accompani- 

 ment to the strictly professional interest of the letters whicli 

 passed between Schnnbcin and Faraday. But, tr.acing as tlicy 

 do, the steps which led to the discovery and isolation of czone, 

 the letters before us are sure to prove of great interest to 

 students of chemistry. 



" P.M'KRS ON MkCH.VMCAI. .Wli I'llVSirAI, SUB.IEf'TS.'' By 



Osborne Reynolds, k.r.s., mkm.inst.c.i-.., ll.d. Volume 1. 

 180',)-1882. (Cambridge University Press.) 15s.net. Professor 

 Reynolds has availed himself of the liberality of the Syndics of 

 the Cambridge University Press, and has had the papers con- 

 tributed by him to the 'Vran^itcOonx of various learned societies 

 and other journals reprinted in a collected form. The 

 present volume is the first of two, and contains the work 

 of tho years 18(10-1882 ; the remaining part, which is not 

 yet ready, will include ])apers down to the present year. Tho 

 chronological order of the essays reveals an interesting 

 peculiarity in the work of most men of science. There is but 

 little continuity in the subjects dealt with year by year. One 

 piece of work sometimes leads to a second of a completely 

 different character, and much time may elapse before tho 

 original research is carried forward toward completion. To 

 obviate this difficulty tlie student consulting the book is 

 provided with two sets of references. When reading earlier 

 papers he is referred forward to succeeding pages on the subjict, 

 and in studying later papers there arc back references given. 

 It will serve to give some idea of tho range of subjects 

 included in Professor Reynolds's researches when it is said that 

 the present volume includes, among many others, papers treating 

 of the tails of comets, the phenomena of thunderstorms, the 

 action of rain to calm the sea, the steering of screw steamers, 

 and the bursting of guns. The steering of ships has been a 

 favourite investigation with Professor Reynolds. Pajicrs 13, 

 19, 21, 2(3, 28, .'ij, and 37 are all concerned with different phases 

 of the all-import;uit question. A second extensive research 

 worked at during these years was that on the dimensional 

 ])roperties of matter in the gaseous state, the account here given 

 of this work runs to 130 large pages. We hope this handsome 

 book will be added to the library of every college where 

 mechanics and physics are taught, and to the reference depart- 

 ment of all large libraries. It is but rarely that a profes.sor of 

 engineering makes such valuable additions to scientific know- 

 ledge outside his own department as are contained in the papers 

 in the present volume. 



"Electric LlinrriNn." By A. C. Swinton. (London: 

 Crosby Lockwood it Son.) 4tli Edition. Illustrated. Is. (rI. 

 That this little book should have attained its fourth edition is 

 to some extent remarkable, for (since it only deals in generali- 

 sations concerning the elements of the subject) one might be 

 pardoned for thinking that the public appealed to had been 

 already more than satisfied. However, so far as the work 

 before us goes, it has the very solid merit of being accurate, 

 technically, though there are some ])assages wherein looseness 

 of expression is to be found. For example, at p. l.!>, one may 

 read ; ''A standard candle is the amount of light derived from 

 a candle .... etc." Now, clearly, if candles can bo derived 

 from the burning of candles, there is very little sense in the 

 burning of any other fuel ! ! But this, in itself, is a trivial 

 matter, though, unfortunately, such verbal slips meet us more 

 than once. Still, be all this as it may, technically the work is 

 accurate, yet, as already suggested, it does not go far. We find, 

 for instance, " Motor generators " discussed and dismissed in 

 the space of those eight lines which come last ! We would 

 suggest both an enlargement and an editor. 



"A Te\t-Biiiik of Zoiii.i)i;v, ■i'kic.\ti:d i-rom .\ Biulooicul 

 St.\nii1'()INT.'' By Dr. O. Schmeil. Translated by R. Rosentock, 

 and edited by .1. T. Cunningham. Parts T. and II. (A. & C. 

 Black.) Illustrated. The dominant idea in this book is the 

 structural adaptation of animals to their inanimate sur- 

 roundings ; and therefore, instead of being a series of dry 

 descriptions of details of anatomy, form, and colouring, it 

 treats of animals as living machines suited to perform particular 

 kinds of work. At least this is stated by the editor to have 

 been the aim of the author ; and, on tho whole, the intention 

 has been fairly well carried out. Tho work is intended for 

 schools and colleges ; and if young students become imbued 



