May 24. 1900] 



NATURE 



77 



the really important pioneering papers from the vast 

 periodical literature that has arisen in Germany during 

 the past ten years. 



In concluding this notice, one is naturally led to re- 

 flect upon the attitude which appears to be still main- 

 tained by a number of English chemists in regard to 

 the modern theories of solution. There can be no doubt 

 that a student reading Dr. Walker's book will become 

 imbued with these theories, and will acquire convictions 

 that will be difficult to eradicate. If these theories are 

 wrong, if they are even strongly suspect, the responsi- 

 bility of the teacher becomes serious It is true Dr. 

 Walker gives here and there some indications of the 

 objections which have been urged against them, but 

 there is no explicit statement of the opposition case. 

 The question arises whether an opposition case can be 

 explicitly stated. The theory of ionic dissociation has 

 been applied to explain and co-ordinate a very large 

 number of chemical facts, and has thrown light on 

 matters that were previously dark. The contention of 

 the objectors appears to be mainly that this light is 

 illusory. The present writer is far from claiming judicial 

 functions in the matter ; but he ventures to think that 

 the opposition to the dissociation theory would be more 

 respected, both here and on the Continent, if it were of 

 a more positive character, and if a more tangible alter- 

 native theory could be presented which should prove 

 itself not less comprehensive and practically productive 

 than the one which is assailed. The history of science 

 shows plainly enough that a comprehensive theory with 

 some weak points will hold its ground until a not less 

 comprehensive theory with fewer weak points makes 

 its appearance. It is probably on this ground that Prof 

 Walker takes his stand in freely imparting the doctrine 

 of electrolytic dissociation to elementary students of 

 physical chemistry. ARTHUR Smithells. 



OUR BOOK SHELF. 



Catalogue of the Lepidoptera Phalacnae in the British 

 Museum. Vol. ii. Catalogue of the Arctiadte (Nolinee, 

 Lithosianre) in the collection of the British Museum. 

 By Sir George F. Hampson, Bart. Pp. xx -f 589, and 

 plates xviii-xxxv. (London : Printed by order of the 

 Trustees, 1900.) 



The first volume of this series, containing the Syntomidit^, 

 was published in 1898, and we have now to welcome the 

 appearance of the second, comprising two groups, which 

 the author treats as sub-families of the Arctiadae ; the 

 typical Arctianic being reserved for the third volume. 

 1 193 species are described in the second volume, all of 

 which, except 162, belong to the Lithosianae, the Nolinae 

 being a comparatively small sub-family. 



The enormous extent of the insect-world is but little 

 realised, even by naturalists, unless they are entomo- 

 logists ; but, considering the progress already made, we 

 are probably well within the mark in saying that it may 

 well take fifty volumes, and the whole of the new century, 

 to complete the Catalogue before us ; and yet the moths 

 are only a portion of one of the seven principal orders of 

 insects, and one which is probably far surpassed in 

 number of species by at least three other orders. 



The descriptions of the species are necessarily brief, 

 but are arranged on a uniform plan which admits of easy 

 comparison ; and their determination is further facili- 



NO- 1595. VOL. 62] 



tated by comprehensive tables of genera and species, and 

 by the large proportion which have been figured, either 

 in the crowded coloured plates, or in text-illustrations. 

 We are glad to see that space has been found for notices 

 of larvjE, when known. Space has also been devoted to 

 phylogeny ; but it is, perhaps, an open question whether 

 it is worth while to deal with this subject in a descriptive 

 work at all. At best, it can only express the momentary 

 and necessarily fluctuating opinions of an individual author 

 on the affinities of genera and species from the very im- 

 perfect materials at present available ; for until the earlier 

 stages of a considerable number of forms have been care- 

 fully studied and tabulated for comparison, it is impossible 

 for us to judge of them completely or accurately. We 

 would therefore prefer to treat this branch of the subject 

 tentatively, in ephemeral publications, rather than to intro- 

 duce a necessarily fluctuating factor, of merely temporary 

 value at best, into a standard work of reference, of such 

 great and permanent value to all lepidopterists as the 

 present. We must also object to the author's tendency 

 to dogmatise on the subject, especially as our knowledge 

 of fossil insects is at present practically nil, and of the 

 early stages of the great majority no better. Such a 

 phrase as [the Arctiada; form] "a family of moths de- 

 rived from the Noctuid^," seems to us quite out of place 

 in a scientific book at the present state of our knowledge ; 

 though a formula which we find a little further on is less 

 objectionable ; " the Nolinae probably arose from a very 

 early Arctian form which had affinities in the Noctuidae 

 to Hypenae and Sarrothripae." 



But these are details of individual taste or judgment; 

 while there cannot be two opinions respecting the value 

 and importance of the work. W. F. K. 



Giordano Bruno, zur erinnerung an den 17 Februar, 

 1600. Von Alois Riehl. Zweite neu bearbeitete 

 Auflage. Pp. iv-f-56. (Leipzig: Engelmann, 1900.) 



Early in 1600 Giordano Bruno went to the stake in the 

 cause of free speech and thought. The ashes of martyr- 

 dom have ere now kept evergreen even reputations and 

 names that were otherwise of little worth. But Bruno's 

 life and work are alike memorable. Few, however, of 

 those to whom the romantic wander-years and heroic 

 death appeal, have leisure and training to grapple with 

 the technical Latin and hard Italian of the versatile and 

 stormy Nolan. The tercentenary, therefore, of Bruno's 

 tragedy can have no memorial more fitting than Prof. 

 Alois Riehl's " Giordano Bruno." Would that it were in 

 English ! Dating originally 1889, Prof Riehl's brochure 

 has undergone revision thorough and throughout. It 

 puts Bruno in his right setting of time and place. It 

 resumes, with brevity and lucidity quite noteworthy, the 

 principles for which Bruno gave his life. Bruno 

 originated neither Copernican physics nor pantheist 

 metaphysics. His debt to one close forerunner at least 

 is not small. Yet in taking the new astronomy as a 

 scientific basis, and only therefrom passing to such meta- 

 physical conceptions as infinity and unity, while reaching 

 out ultimately to a monistic principle, it is Bruno and 

 not his precursors, physicist and revived neoplatonist, 

 that may claim to father modern naturalism. Prof Riehl 

 characterises the system as " theocentric," since nature 

 is, for Bruno, deus in rebus. Bruno is said to have met 

 the process which resulted in his condemnation by 

 equivocating between what he accepted secundum fidem 

 and what he affirmed secundum rationem. At any rate, 

 whatever human weakness he may have shown, he lost 

 no opportunity of reaffirming his principles. He recanted 

 nothing. He could have saved himself would he but 

 have prostituted his pen to apologetics on behalf of the 

 reigning orthodoxy. He chose not propter vitatn 

 Vivendi pcrdere causas. And he died a knight-errant of 

 the free spirit. H. W. B. 



