Jan. 15, 1874 j 



NA TURE 



in French millimetres, and not in parts of German inches, 

 which require reduction. 



As the asci vary much in length, only the thickness 

 is given, though, under certain circumstances, as in 

 Sphasrioe, it is often quite as variable as the length. In 

 one or two instances we should have been glad to see 

 more critical remarks, as, for example, under /\'^/;(i vi-nosa, 

 where the larger figure so e.xactly accords with that of Fries 

 in the " Atliga och giftiga Svampar" of Disdna pcrlata, 

 that we should have been glad to have heard whether 

 there is any real distinction between the two. As we used 

 to find it every spring in our younger days, it was more 

 like the figure of Greville's Pcziza reticulata, than that 

 before us. Something again might have been said re- 

 specting the resemblance of our author's very curious 

 Pt'^ha corium, to the North American Peziza craten'iuii 

 with which it has evidently a close affinity. There is, we 

 think, no doubt that the Verpa dii^itatiforiiiis of England 

 is the same with that figured by Herr Weberbauer. We 

 shall be truly glad to find that this beautiful work meets 

 with such success as to ensure its continuance. 



It is quite curious to observe how an interest in fungi 

 has rapidly increased in this country. The late Fungus 

 Show at South Kensington was so well attended that the 

 Council offer for next year a very ample list of figures 

 and as especial prizes are to be given for collections of 

 novelties, or for cultivated species, the meeting will be 

 one of much importance. Even in Scotland, where a 

 short time since fungi were looked on as " abominations,'' 

 there is a very active movement in their favour, especially 

 amongst the clergy, v/ho have made some very interesting 

 additions to our Mycology, and a fungus-show is pro- 

 jected next autumn at Aberdeen. In England, where 

 some of the older students are passing away, it is a great 

 pleasure to know that the subject is taken up by such 

 strictly scientific observers as Mr. Plowwright, Mr. Renny 

 and Mr. Phillips, not to mention many other names of 

 great promise. M. J. BERKELEY 



OUR BOOK SHELF 



JuYlon's Sdi'/ice, Art, and Literaiun: A Dictionary of 

 Universal Information ; comprising a complete Sum- 

 mary of the Moral, Mathematical, Physical, and Natu- 

 ral Sciences ; a Plain Description of the Arts ; an 

 Interesting Synopsis of Literary Knowledge ; with the 

 Pronunciation and Etymology of every leading term. 

 Containing nineteen hundred and eighty Columns, and 

 upwards of six hundred Engravings. 2 vols. (Lon- 

 don : Ward, Lock, and Tyler. No date.) 



This book does not pretend to be, and very evidently is not, 

 more than a compilation from other cyclopajdias, and from 

 works on the various subjects of which it treats. So far as 

 we have examined it, most of the mformation contained 

 in it is derived from the former source, and it is 

 impossible that any thoroughly trustworthy re^erence- 

 bock can be compiled in this manner, especially if the 

 compiler or compilers have no special knowledge of 

 the subjects with which they deal. The work pretends to 

 give only a summaty of facts, but in many of the articles 

 much space is wasted by comment and reflection. There 

 is absolutely no article on the Spectroscope, which is 

 referred to Spccinim, an article without any illustrative 

 cut, occupying one-third of a column, that might have 

 been written twenty years ago. Why is there no article 

 Evohidoii? and vhy, \mi.zx Development, \i\\\<i greater 



part of the short article occupied with the " Vestiges of 

 Creation," and no reference whatever made to the state of 

 the doctrine in Germany and America ? Under the very 

 specific heading Cranno^es the general subject of Lake- 

 dwellings is discussed, the writer evidently not being 

 aware of the important distinction between the Crannoges 

 of Ireland and the Lake-dwellings of Switzerland. A 

 very poorly-executed copy of Keller's restoration of a 

 Swiss lake-dwelling is the illustration to the article 

 Crannoges. We say again no work of this kind can be 

 regarded as a standard reference-book unless the editor 

 has at his command a band of master specialists. 

 The illustrations, as a rule, are inferior, and many of 

 them seem well worn ; many, moreover, are totally use- 

 less, such as those put beside the article Draiving and 

 similar articles, which seem to be inserted simply to make 

 the book take with a certain class. We think there is 

 still room for a comprehensive reference dictionary con- 

 taining information on all subjects compactly put together. 

 No one at the present day, when there are such multi- 

 tudes of special treatises in every department of human 

 knowledge, would ever think of resorting to an ency- 

 clopedia to study a subject ; and thousands, we believe, 

 would be thankful for an all-comprehensive reference- 

 book which should present in the briefest possible space 

 the leading and latest facts under each heading free of all 

 comment and speculation. Such a v/ork might be as 

 comprehensive as the " English Cyclopaedia," or the 

 " EncyclopEedia Britannica," perhaps more so, and yet not 

 exceed in bulk of matter the work at the head of this 

 notice. All the scientific articles in such a work, however, 

 and many others besides,could onlybe written satisfactorily 

 on such a plan by men of special knowledge in each de- 

 partment ; such men alone can judge what is of primary 

 and what is of secondary importance. 



Scientific Handicraft ; A Descriptive, Illustrated, and 

 Priced Catalogue of Apparatus. Vol. I. Mechanics, 

 Hydrostatics, Hydrodynamics, and Pneumatics. By 

 J. J. Griflin. F.C.S. Pp. 186. (London, 1S73). 



This is a useful Catalogue of Apparatus, which contains 

 an account of the method of using the principal pieces of 

 apparatus which are described. There are also sugges- 

 tions for keeping instruments in good order. It will be 

 found useful by those who select apparatus for purposes 

 of school leaching or public lecturing ; and Mr. Griftm 

 has done good service by endeavouring to introduce as 

 many new forms of apparatus, or modifications of old 

 forms, from Germany and France, as he could obtain 

 knowledsre of 



LETTERS TO THE EDITOR 



\The Editor does not hold himselp responsible for opinions expressed 

 by his correspondents. No notice is tal;en of anonymous 

 communications. ] 

 The Shrinking of the Earth and Terrestrial Magnetism 



Since writing my previous letter (vol. ix. p. 141) I liave received 

 a note from Mr. Darwin, who says that in his work on "Coral 

 Reefs," he arrived at the conclusion that volcanoes are not found in 

 areas of subsidence. As I have succeeded, I thinlt, in eliminating 

 them from areas of upheaval, it may be that they occupy the boun- 

 dary line of the oscillating land, and are stationed on or near the 

 fissures and joints along which the er-rth's crast has given way. 

 At all events, I invite a cari-fal examination of those areas which 

 we know to be rising, such as the northern circumpolar region, 

 Australia, &c., in the firm conviction that volcanoes will not be 

 found on any of them. 



On another point I am very glad to say Mr. Darwin agrees 

 with me, and I am therefore supported by his great authority. 

 He tells me that in his work on "Volcanic Inlands" he 

 arrived at the conclusion that the great continents are rising, and 

 the ocean beds sinking. This, of course, is only an hypothesis, 

 and will remain so until the world has been carefully surveyed, 

 1 ut the large nun-jl-er of facis I have collected, and which vvil), 



