268 



NA TURE 



[July 19, 1906 



text-book. Such a work should appeal to the teacher 

 and to the student as a work of reference, and also to 

 the outsider, it may be a worker in another department 

 of science, who wishes to understand what the 

 science of chemistry now is without being confronted 

 with all the bewildering and conflicting details of 

 the subject, such as the advanced student may find 

 in Watts 's Dictionary or in many German works on 

 chemistry. 



Such a treatise, perfect as a broad and general 

 description and discussion of the science of chemistry, 

 has not yet been written in English. Roscoe and 

 Schorlemmer's treatise, however, still remains the 

 nearest approach to the ideal. 



POPULAR EVOLUTIONARY THEORY. 

 Darwinism and the Problems of Life; a Study of 



Familiar Animal Life. By Prof. Conrad Guenther. 



Translated by Joseph McCabe. Pp. 436. (London : 



A. Owen and Co., 1906.) Price 12s. 6d. net. 

 ""pHIS is a disappointing book. The idea of using 

 *• the common sights and sounds of nature which 

 are open to general observation as material for build- 

 ing up a detailed comprehension of evolutionary theory 

 is a good one; there is much to be said for the in- 

 ductive system of instruction as a supplement to the 

 deductive methods more often employed. But in this 

 particular instance the errors in matters of fact are 

 so prominent and so numerous as to overshadow 

 such merit as the plan of the work possesses. Some 

 of these mistakes must be laid to the charge of the 

 translator, who obviously is but imperfectly acquainted 

 with the subject-matter of his original, and whose 

 want of due care appears in the occurrence of such 

 phrases as " the grouping of their elements is dif- 

 ferent from in dead albumen," " Pentastomum has 

 little of the characteristics of a spider, to which it 

 really belongs," and of such unwonted forms as 

 *' terrestial," " adaption," " caracoid," " strepsitera " 

 — the last two being found more than once. " Sexu- 

 ally," on p. 301, is clearly intended for " non- 

 sexually. " "An example of a genius under the 

 geheric title " is capable of easy emendation, but 

 " weel " (p. 220) almost baffles conjecture. Can it 

 be meant for " valve "? 



The " processionary butterfly " is, of course, a 

 moth; the "tentacles" of the stag-beetle (p. 91) are 

 apparently its mandibles ; we hear for the first time of 

 the " bones " of articulates, and that our muscles 

 are "secretory products." It is implied on p. 143 

 that the adder is not poisonous. This is surprising 

 until we find from other passages that the author's 

 " adder " is not an adder at all, but the harmless 

 ringed snake. A sentence on p. 226 is absolutely 

 unintelligible, unless we may conjecture that the word 

 " falls " is an attempt to render the German " Falle," 

 here obviously used in the sense of " cases." 



It is charitable to the author to suppose that not 

 he but his translator is responsible for the statement 

 that " in the case of moths and grasshoppers there 

 is not a very great difference in habits between the 

 larva and the imago." But when we find it stated 

 NO. 1 916, VOL. 74] 



that " in the grasshoppers the front extremities have 

 become a powerful leaping apparatus"; that an 

 insect is covered with "dust" by the "stigma" 

 of a flower; that " if we take two beetles that seem 

 absolutely like each other and only differ in size " 

 they are of different species; that "the frogs have 

 only one chamber to the heart"; and that "iron 

 is always found combined with sulphur," it is diflfi- 

 cult to avoid the conclusion that the author has to 

 answer for mistakes of his own. 



There are advantages in using the popular names 

 of natural objects in a book intended mainly for the 

 unlearned. But a protest must be entered against 

 the slovenly habit, too common with translators, of 

 contenting themselves with a literal rendering of such 

 names into another language. How, for example, 

 is the English reader to identify the " small nocturnal 

 peacock's eye "? If the scientific name be disallowed, 

 at least the recognised English popular title should 

 be given. 



Many of the author's conclusions on the main 

 subject are sound enough. It is the more to be re- 

 gretted that his statements of fact are so often open 

 to adverse criticism, and that he has been, on the 

 whole, so badly served by his translator. F. A. D. 



OUR BOOK SHELF. 



.iiifnahme tind Analvie von Wcchselstromkiirven. 



By Dr. Ernst Orlicli. Pp. viii -1-117. (Brunswick: 



F. Vieweg and Son, 1906.) Price 3.50 marks. 

 In the usual handbooks on alternating currents the 

 methods of study of the wave-form of the alternations 

 and the analysis of the curves of E.M.F. and current 

 obtained are usually treated very scantily. Recently, 

 however, the subject has attracted considerable atten- 

 tion, and its importance to a station engineer, who 

 wishes to make alternators not identical in design run 

 well in parallel, is now recognised. 



Prof. Orlich, of the Reichsanstalt, has endeavoured 

 in this little book to present a clear account of what 

 is known on the subject. It begins by definitions and 

 a short mathematical introduction to the use of 

 Fourier series, &c. Then follow descriptions of various 

 methods of taking curves by the point-to-point pro- 

 cess, and of the apparatus of Rosa, of Callendar, and 

 of Hospitaller's " Ondographe. " 



The Braun tube is described and illustrated, but no 

 mention is made of the fact that owing to the kathode- 

 ray bundle not being composed of rays of the same 

 magnetic deflectability, and the consequent lack of 

 sharpness of the moving image, its use for the study 

 of alternating currents is limited rather to qualitative 

 than to quantitative work. The next chapter deals 

 with oscillographs in their various forms. Their theory 

 is discussed, and the advantages of the different 

 patterns of moving needle and bifilar instruments 

 pointed out. 



The recent experiments on telephony of Mr. Duddell, 

 and the wonderful curves shown by him at his recent 

 lecture at the Royal Institution on the analysis and 

 transmission of sounds, show that substantial advances 

 have recently been made in the construction of very 

 sensitive oscillographs of his pattern, the curves of 

 currents furnished by an ordinary microphone being 

 readily shown to a large audience. 



After a chapter on the phenomena of resonance, the 

 concluding portion of the book deals with the analysis 

 of curves, with descriptions of the best-known forms 



