5/6 



NA TURE 



[October 13, 1904 



although, of course, the author is only using the term 

 coniinonly applied to these instruments. 



Dr. Lehfeldt then discusses the mechanism of 

 electrolytes. We are not sure what a certain school 

 of chemists will say to the following rather didactic 

 statement : — 



" It was Arrhcnius who first put forward reasons for 

 supposing that an electrolyte might be largely, . . . 

 dissociated in solution . . . this view has gradually 

 gained support from experiment since, and may be 

 looked upon as thoroughly established." 



Dr. Kahlenberg, for instance, would hardly sub- 

 scribe to this statement. In this chapter the author 

 also deals, among other subjects, with the conductivity 

 of the electrolvte, ionic velocities, and electrolysis in 

 non-aqueous solutions. 



The last chapter is devoted to the theory of chemico- 

 electromotive force. The section on thermodynamic 

 theory and the calculation of electromotive force of a 

 voltaic cell well repays perusal, as does the section on 

 standard cells. 



Dr. Lehfeldt is thoroughly at home with his sub- 

 ject ; we are not, however, sure whether the average 

 student will find the style very interesting. Of course, 

 a book of this kind cannot be read in a cursory way; 

 if it could, we doubt whether it would be worth read- 

 ing, but we are of the opinion that it will be welcomed 

 by all interested in the subject. 



1'races of the Norse Mythology in the Isle of Man. 

 By P. M. C. Kermode. Pp. 30. (London : Bem- 

 rose and Sons, Ltd., 1904.) Price 2S. 6d. 

 In this work Mr. Kermode, whose name is well known 

 in connection with Man.K archeology, has printed a 

 lecture delivered to the Antiquarian Society of his 

 native island in December of last year. The Isle of 

 Man contains a large number of cross-bearing grave- 

 stones, which, as the inscriptions clearly show, belong 

 to the period when the Scandinavian element was pre- 

 dominant in the island. It is not improbable that in 

 some cases the symbols on these stones may refer to 

 the old Scandinavian mythology rather than to 

 Christian belief and legend, and Mr. Kermode has 

 endeavoured to determine how far this is the case. 

 After a verv brief sketch of the Scandinavian settle- 

 ments in the west, and more especially in Man, a short 

 account is given of some leading details of the old 

 ■Norse mythology as preserved in the Eddas. Both 

 here and in the following section an interest in the 

 subject is sometimes more evident than familiarity 

 with it in all its bearings. It is, for example, quite 

 c rroneous to state that " of the seven days of the week 

 all but the first two are called after Scandinavian 

 iL;ods." Even on his own lines, Mr. Kermode cannot 

 thus account for Saturday, and. a closer study of the 

 old English forms would have shown him the true 

 origin of the other names. The influence of the 

 Scandinavian tongues on English has been very great, 

 but it requires a close study of philology to decide the 

 particular cases in which it appears. 



The concluding section consists of a detailed de- 

 scription of the illustrations, under eight heads, and 

 with references to the ten plates at the end of the 

 booklet. These are neatly executed, and exhibit 

 tvpical specimens of Celtic crosses and ornamentation, 

 as well as the symbolic figures which Mr. Kermode 

 believes to represent subjects taken from the old 

 mvthology. In many cases the explanation he oflers 

 is extremelv doubtful, as there is always an equal, if 

 not greater, possibility that the symbols are of 

 Christian origin. Thus, what Mr. Kermode takes to 

 be an eagle ( = Suttung) pursuing a falcon f = Odin), 

 might equally well, for all one can see, represent 



NO. 1824, VOL. 70] 



Noah's raven and dove. The harper whom he 

 identifies with the " gladsome Eggth^r " of Voluspd 

 may just as well be King David ; and if the fish is a 

 Christian symbol on Plate X., why not also on 

 Plate III.? In many of these cases it is probably 

 hopeless to determine what the sculptor had in his 

 mind, and there is no particular gain in making 

 guesses at it. 



In minor points there is not always as much pre- 

 cision as is desirable. The Icelandic words and names 

 are too frequently misprinted, while such equations as 

 Hnikarr and nykr, Rig and Eirik, are evidence of 

 shaky philology. Mr. Kermode's lecture, however, 

 may be of service in helping to waken or encourage 

 interest in that Scandinavian influence on Britain 

 which is an important factor in the history of our 

 country. W. A. Craigie. 



Eton Natiirv-sliidv and Observational Lessons. Part ii. 



By M. D. Hill and W. M. Webb. Pp. xvi+ 174. 



(London : Duckworth and Co., 1904.) Price 3s. 6d. 



net. 

 Part ii. of this book, like part i., is excellent. That 

 nature-study as here recommended is educationally 

 sound is beyond dispute. \\'hat makes instruction so 

 wearisome to the learner is often, to put it plainly, 

 the unceasing sound of the schoolmaster's voice. 

 What a boy, if he has any go in him, wants, is to do 

 something for himself. It would be best if he could 

 make out everything unaided. " I never tell my pupils 

 anything," once said a mathematician devoted to the 

 maieutic method; and Hesiod quaintly remarks, " The' 

 best man of all is he who finds out everything for him- 

 self." But this is hardly possible for us moderns, and 

 the authors of this book are wise enough not to make 

 a craze of a sound principle. In the chapters, to take 

 examples, on earthworms, woodlice, the defensive 

 armour of plants, and plants that have no flower, there 

 is plenty of information given to stimulate interest. 

 If the pupil is the right kind of boy, he will be keen 

 to follow some of the lines of investigation pointed out. 

 Many persons are led to the out-of-doors study of 

 natural history by reading. They want to see some of 

 the wonderful things that naturalists have seen, not 

 always to get them at second hand. Indeed, the 

 importance of reading in connection with observation 

 should be insisted on. Many boys, though full of zeal, 

 never get beyond a very restricted field in natural 

 history, because they will not read in order to discover 

 how the little that they have learnt by the use of their 

 own eyes finds its place in the vast accumulation of 

 knowledge. The observer should be a reader, and the 

 reader an observer. 



A great deal may be learnt by trying the experiments 

 recommended in this book, e.g. by hatching trout eggs, 

 by keeping a fresh-water aquarium or an observatory 

 hive of bees, by making a formicarium, by photograph- 

 ing such things as birds and birds' nests. But here a 

 difficulty arises. At school, how is a boy to keep an 

 observatory hive of bees or to hatch trout eggs? In 

 fact, some of the suggestions bring out sadly the limit- 

 ations of school life. Others, no doubt, are quite 

 possible. But headmasters might well study a book 

 like this. If teaching is to proceed on a truer and 

 more natural plan than hitherto, something must be 

 done to remove existing restrictions. 



The subjects for observation (e.g. a frog's egg, a 

 hen's egg, the development of tadpole and chick, a 

 silk worm, an opening flower) are well chosen. The 

 illustrations are all good. Some of the photographs 

 ought to induce boys to make their photography a help 

 to accurate observation instead of a mere amusement. 



