576 



NA TURE 



{April 23, 1885 



Wyville Thomson assigned the name Metacrinus, though 

 without defining its distinctive characters. No fewer than 

 eleven species of this genus were dredged by the Chal- 

 lenger j and, previously to his receiving this collection, 

 Dr. P. H. Carpenter had come to the knowledge of three 

 other species, a description of which he has communi- 

 cated to the Linnasan Society. All these seem very 

 limited in their geographical range, and not one of them 

 has been found in the Atlantic. No fossil representative 

 of this genus is at present known ; but it is by no means 

 impossible that some of the Liassic (reputed) Pentacrini 

 may prove to belong to it. 



In addition to the 2S plates drawn for Sir Wyville 

 Thomson, and 5 of Peiitacrinus wyville-thomsonii sup- 

 plied by Dr. W. B. Carpenter, 35 plates have been drawn 

 under Dr. P. H. Carpenter's direction, many of them 

 containing numerous figures ; while another has been 

 autotyped from micro-photographs prepared by himself ; 

 making a total of 69 plates, for the most part admirably 

 executed, besides 21 woodcuts in the text. When we 

 add that the work is provided with a copious bibliography 

 and an excellent index, we hope that we shall have made 

 it clear that nothing, in our judgment, is wanting to its 

 completeness. — The report on the Comatulidce, of which 

 the preparation was far advanced before it was put aside 

 for that on the stalked Crinoids, will, we trust, speedily 

 follow. We shall next look for the monograph of the 

 Blastoidea, on which, it is understood, Dr. P. H. Car- 

 penter has been for some time engaged, in conjunction 

 with Mr. R. Etherege, jun., and which will, we believe, 

 throw an altogether new light on that most interesting 

 group. And every British Palaeontologist, we feel sure, 

 will desire that he may then find himself enabled to under- 

 take, on the sure basis he has now laid, a complete re- 

 view of the Fossil Crinoidca and a re-investigation of the 

 little-understood Cystidea. 



FRANKLAND AND JAPP'S INORGANIC 

 CHEMISTR V 

 Inorganic Chemistry. By Edward Frankland, Ph.D., 

 D.C.L., LL.D., F.R.S., Professor of Chemistry in the 

 Normal School of Science ; and Francis R. Japp, M.A., 

 Ph.D., F.I.C., Assistant Professor of Chemistry in the 

 Normal School of Science. (London : J. and A. 

 Churchill, 1884.) 



WHEN one opens a new book on Chemistry written 

 by men who are generally recognised to be 

 masters of their subject, one expects to find some light 

 thrown on the great and confused heap of details with 

 which one is accustomed to be confronted in the pages 

 of the ordinary chemical text-book. 



Hydrogen, it is true, can scarcely be expected to have 

 changed its properties since the last treatise on descrip- 

 tive chemistry was published ; it still remains "a colour- 

 less gas devoid of taste and smell " ; it is still a fact that 

 "' owing to its lightness this gas may be collected in 

 inverted vessels by upward displacement." No one will 

 venture to dispute the assertions that " in the free state 

 hydrogen occurs in the gases of volcanoes (Bunsen)," or 

 that " in combination hydrogen occurs in enormous 

 quantities in water." But we have heard these state- 

 ments so very often. Are they not preserved for us in 



the pages of scores of books, and of tens of scores of 

 pamphlets? Surely it is not asking too much from our 

 masters in chemistry that they should begin to make 

 some use of the many facts which have been so laboriously 

 collected. The " hewers of wood and drawers of water " 

 have brought the materials into the camp : must they lie 

 there for ever unused ? They have been scheduled and 

 catalogued a thousand times ; was it necessary or advant- 

 ageous thaf Profs. Frankland and Japp should undertake 

 the work of issuing another catalogue ? 



The book before us contains 783 pages of printed 

 matter ; of these, 650 pages are devoted to descriptions 

 of the elements and their compounds. One cannot expect 

 much in this part of the book, except a repetition of the 

 well-known facts. The formulas in this book are perhaps 

 a little more picturesque than usual ; the judicious em- 

 ployment of thick type and small o's, whether commend- 

 able or not from the chemical point of view, certainly 

 gives an air of distinction to the page which the ordinary 

 text-book is obliged to do without. 



Turning to the introductory chapters, one is somewhat 

 taken aback to learn on page 1 that cohesion, heat, light, 

 gravity, chemical affinity, and electricity, are all forms of 

 force. After learning this, one is certainly not surprised 

 to be informed (pp. 64-5) that the formulae H — C — H 



II 



n, 



and = C = o, "give no indication that the molecule of the 

 first compound contains a vast store of force, whilst the 

 last is, comparatively, a powerless molecule." This con- 

 fusion between force and energy is painfully visible 

 throughout the book. Is there something radically 

 absurd in the attempt to apply dynamical notions to 

 chemistry ? If not, why is it that when a chemist commits 

 himself to a statement involving the conceptions force 

 and energy in nine cases out of ten he gets altogether 

 confused ? 



A great part of the advance made in chemistry in 

 recent years is based on the adoption of clear and 

 practical definitions of the atom and the molecule, and 

 on the conceptions which flow from these definitions. 

 Chapters IV., V., and VI. of Profs. Frankland and Japp's 

 book deal with these subjects. Chapter IV. gives a clear 

 and trustworthy account of the laws of chemical combi- 

 nation ; Chapter V. deals with the atomic theory in an 

 exceedingly satisfactory manner ; and Chapter VI. pre- 

 sents us with a sketch of the methods whereby the 

 molecular weights of gaseous elements and compounds, 

 and the atomic weights of elements, are determined. 

 These chapters appear to us to be especially good ; a 

 careful study of them is likely to be of much benefit to 

 the student of chemistry. But if the student be of a 

 critical turn of mind, he may object that he should be 

 shown the " steep and thorny way," while the authors 

 themselves, in the other parts of their book, "the primrose 

 path of dalliance " tread. Thus, to take an instance, the 

 molecular formula of ferric hydrate is given (p. 59, note) 

 as Fe-jH^O,; ; but ferric hydrate has never been gasified, 

 and the theory of molecules as developed in Chapter VI. 

 is a theory strictly applicable to gases only. Indeed, we 

 might object to the incongruity between the teaching of 

 Chapters V. and VI., and the practice of most of the 

 book. These chapters define atom and molecule, and 



