148 



r NA TV RE 



\June 14. 1883 



OUR BOOK SHELF 

 Die Welch- unci Sehaltiere gemeinfasslich Dargestellt. 



Von Prof. Ed. von Martens. (Leipzig: G. Feytag ; 

 Prag: F. Tempsky, 18S3.) 

 " CONCHOLOOY is ris ! " was the pithy remark of the 

 lamented Edward Forbes, made in his cheeiy way about 

 forty years ago, when Mr. James Smith of Jordan Hill 

 directed his attention to the arctic nature of some fossil 

 shells in the Clyde district. Capt. Brown, however, had pre- 

 viously but unconsciously published the same hypothesis, 

 which has been lately confirmed and extended by the 

 discoveries of Messrs. Steele and Scott at Glasgow. 

 Since the above remark was made by Forbes the study 

 of the Mollusca has in a general point of view marvel- 

 lously increased and become popularised by innumerable 

 publications. We have now no fewer than six periodical 

 works on the subject, English, French, Belgian, German, 

 Italian, and American, besides four most useful manuals 

 in English, French, German, and American. The German 

 and latest manual, now before me, has been written by 

 an experienced conchologist whose father (Georg yon 

 Martens) was favourably known to science nearly sixty 

 years ago by his " Reise nach Venedig." The pre- 

 sent author may therefore be considered an hereditary 

 naturalist. 



The manual of Prof, von Martens differs from that of 

 Dr. Paul Fischer ("Manuel de Conchyliologie ") which 

 is in course of publication, as well as from Woodward's 

 " Manual," in its plan and popular mode of treatment, 

 although all these works are equally good. The present 

 treatise on the soft or naked and shelly Mollusks forms a 

 small octavo handbook of 327 pages, and is illustrated by 

 205 figures. The principal contents of the work are as 

 follows : — 



(1) Names and position in zoology ; (2) The shell 

 in general ; (3) Organic structure of the Mollusca ; (4) 

 Cephalopods ; (5) Univalve shells, Nudibranchs, Hetero- 

 poda, Pteropoda, and Solenoconchia ; (6) Bivalves ; (7) 

 Habitat and geographical distribution ; (8) Enemies and 

 use of the Mollusca. The illustrations are excellent ; 

 they are not arranged in plates, as in the manuals of 

 Woodward and Fischer, but are dispersed throughout the 

 work in their appropriate places by way of explanation. 

 This is in some respects an improvement, although it 

 causes an unnecessary repetition of the same figures. For 

 instance Margaritana margaritifera (why not Unlo 

 margaritifer f) is figured three times in pp. 196, 221, and 



3 11 - 



The curious varieties or monstrosities of Planorbis 

 multiformis, a tertiary shell from Steinheim, are well 

 shown in Fig. 128. I am very glad to see that the author 

 is by no means addicted to an excessive multiplication of 

 genera and species, which is the normal failing of so 

 many Continental conchologists, especially in the land 

 and freshwater shells. In the Pteropoda he has rightly 

 adopted Pallas's generic name Clione (1767-1774) for C. 

 borealls, instead of Miiller's name Clio (1776), which 

 Fischer has used in the reverse sense. Clio of Linne' 

 (founded on Browne's genus and Jamaican species) is 

 wrongly represented in the manuals of Fischer and von 

 Martens by Cleodora of Lamarck. As no review or notice 

 of any book is regarded as complete or satisfactory with- 

 out a dash of criticism, however slight, I would venture to 

 suggest a few corrigenda for the next edition. It is im- 

 possible to distinguish Helix hortensis from //. nemoralis, 

 except as a variety, the former being more northern and 

 the latter more southern in geographical distribution. 

 Hyalcea of Lamarck (1810) ought to be Cavollna of 

 Gioeni (1783) and Abildgaard (179O. not of Bruguiere 

 (1792) ; Lortpes is not a synonym of Lucina, but a dis- 

 tinct genus, and Sphtrrium is a much older name than 

 ( 'yclas. But I make these few remarks more for the con- 

 sideration of the author than from any pretence on my 



part to be a judge. I can heartily and conscientiously 

 recommend this manual not only to the scientific but to 

 the ordinary class of readers. J. Gwyn Jeffreys 



Notes on Qualitative Analysis, Concise and Explanatory. 



By H. G. H. Fenton. (Cambridge University Press, 



1H83.) 

 These are ordinary tables of reactions of the " more 

 common metals and acids," and also of some of the 

 "more common organic bodies." The organic bodies 

 include carbohydrates and a few alkaloids. 



It is very strange that the farce of common and rare 

 elements is still maintained in nearly all the tables and 

 books on qualitative analysis. Surely such elements as 

 titanium and tungsten and molybdenum and selenium or 

 lithium are common enough, at any rate in laboratories, to 

 have a place given to them in analysis books, not to men- 

 tion thallium, glucinum, and cerium, which do occur in 

 minerals, to the no small mystification of the poor student 

 crammed up with tables of analyses of " common metals." 

 There are rather too many empty pages in these "Notes," 

 and the size is inconveniently large for working with on a 

 laboratory bench. 



Practical Chemistry, with Notes and Questions on Theo- 

 retical Chemistry. By William Ripper, Science Master, 

 Sheffield Board School. (London: Isbister, 1883.) 



These notes and questions, mostly questions, have been, 

 as the author explains, compiled to prepare students and 

 teachers for the examinations of the Science and Art 

 Department. It is to be regretted that such books are 

 required, for although, as the author states in his preface, 

 th arrangement may have been very successful in "pass- 

 ing" students, it is questionable whether the information 

 and knowledge obtained are of such a nature as to be 

 valuable afterwards. The book is well adapted for its 

 purpose, that of cramming. 



LETTERS TO THE EDITOR 

 {The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, 

 or to correspond with the -writers of, rejected manuscripts, 

 No notice is taken of anonymous communications. 

 [ The Editor urgently requests correspondents to keep their letters 

 as short as possible. The pressure on his space is so great 

 that it is impossible otherwise to insure the appearance even 

 of communications containing interesting and novel tacts.] 



The Matter of Space 

 Will you permit me to express my thanks to Prof. Herschel 

 for his flattering review of my paper on "The Matter of 

 Space," in Nature, vol. xxvii. p. 349? It is certainly grati- 

 fying to find that the views which I deduced from the ordinary 

 relations of moving matter are confirmed by the results of mathe- 

 matical analysis and it is a source of satisfaction to me to have 

 called forth such a studied and thorough treatment of the subject 

 as Prof. Herschel has given it. I cannot but retain my view < f 

 the unity in character of all substance, to which he objects, yet 

 in that respect our opinions diverge but slightly, since I replace 

 ether with excessively disintegrated matter, and he considers the 

 particles of ponderable matter to consist of aggregates of ethereal 

 substance. An ether whose condensation yields particled matter 

 answers all the requirements of unity of substance. 



As the subject is under discussion, there are some further 

 points in the motor relations of particles which it may be well to 

 indicate. It is highly improbable that the molecules of matte--, 

 even if it be in the state of a rare gas, wander at will, constantly 

 changing their relations of position to other molecules. More 

 probably there is very little independent change of place, each 

 molecule being usually held as a close prisoner in a nest of sur- 

 rounding molecules. The grouping of molecules may be changed 

 by the action of external agencies, but a new molecular equili- 

 brium tends to be quickly established. Such seems the general 

 tendency of nature. If some of the molecules in a mass of 

 substance have an independent motion, friction soon disseminates 

 that motion, and brings them into harmonious conformity wuh 



