460 



NA rURE 



[March 15, 1888 



rather to be referred to the quartz-keratophyres than to 

 the quartz-porphyries (p. 418). 



We are glad to see that oHvine is no longer regarded 

 by the author as an essential constituent of basalt. This 

 rock-name is thus made to gain considerably in signifi- 

 cance, since it now embraces all (neo-)volcanic rocks of 

 basic composition which essentially contain plagioclase 

 and augite, whether they occur as lava-sheet or dyke. 

 The acid plagioclase-augite rocks, on the other hand, 

 whether with or without olivine, are referred to the 

 andesites. 



In connection with the basalts, it may be of interest to 

 point out how considerable an alteration in the minor 

 subdivisions of a rock-group has been produced by 

 modern microscopic research. The old familiar grouping 

 of the basalts, according to their granular texture, as 

 dolerite, anamesite, and basalt, has been superseded. 

 The modern petrographer distinguishes, with Prof. Rosen- 

 busch, between the following structural varieties, which 

 may coexist with any granular dimension: (i)"hypidio- 

 morphic granular,? (2) " intersertal," (3) "holocrystalline- 

 porphyritic," (4) " hypocrystalline-porphyritic," and (5) 

 " vitrophyric." 



Welcome additions to the book are an appendix to the 

 invaluable literature-index of Vol. I., bringing it up to the 

 present date ; and a useful index of localities, compiled 

 by Dr. H. B. Patton. The book is well got up, well 

 printed, dnd remarkably free from typographical errors. 



F. H, Hatch. 



A TREATISE ON CHEMISTRY. 

 A Treatise on Che/nistry. By Sir H. E. Roscoe, F.R.S. 

 and C. Schorlemmer, F.R.S. Vol. III. The Chemistry 

 of the Hydrocarbons and their Derivatives ; or, Organic 

 Chemistry. Part IV. (London : Macmillan and Co., 

 1888.) 



THE present instalment of this well-known work deals 

 with those benzenoid compounds containing respect- 

 ively seven and eight atoms of carbon. 



The excellent features referred to in our notices of the 

 previous parts are preserved in this new section. The his- 

 torical portions are especially valuable. Most text-books 

 of organic chemistry restrict themselves to giving an 

 account of the existing state of the science ; but in the 

 present work the description of every important com- 

 pound, or group of compounds, is prefaced by an historical 

 review of the various investigations which have led up, 

 step by step, to the views now held. To students of 

 organic chemistry, who, in ninety-nine cases out of a 

 hundred, never see the older memoirs (and, if they did, 

 would probably only be bewildered by the obsolete 

 nomenclature and formulae), these historical introductions 

 are a great boon. As instances of this interesting mode 

 of treatment, we may cite the historical introductions to 

 the subjects of toluene, of the nitrotoluenes, and of creosote 

 — with the account, in the latter case, of the confusion 

 between creosote and phenol, and of the way in which 

 this confusion was eventually cleared up. In this con- 

 nection we may call the attention of our spelling re- 

 formers among English chemists to the passage (p. 33) 

 quoted from Reichenbach's original memoir in which 

 he first coins the word "creosote." The etymological 



knowledge of the average English chemist (when 

 it exists at all) is little — and dangerous, He has 

 learned that there is such a word as n^eas, and 

 rashly opining that he is at liberty to derive an English 

 word from a Greek nominative, he changes Reichen- 

 bach's spelling to " crcf^sote " — a corrupt form which, as 

 " creasotum," has passed into the Pharmacopoeia, em- 

 balmed in the choicest apothecaries' Latin. One regrets 

 that the zeal of the reformer was not tempered by the 

 knowledge that Reichenbach derives the word from the 

 contracted genitive, xp/wy.i 



The descriptive portion of the work is full and accurate. 

 The only case that we have noticed in which the informa- 

 tion is not up to date is in the account of the benzalde- 

 hydines (pp. 141 and 142), which are represented as 

 ordinary condensation-compounds of ortho-diamines 

 with benzaldehyde ; whereas Hinsberg showed, about a 

 year and a half ago, that they are in reality benzylated 

 anhydro-bases. The name " Nevile " is also throughout 

 erroneously given as " Neville." 



OUR BOOK SHELF. 



A Text-book of Organic Materia Medica. By Robert 

 Bentley, M.R.C.S., F.L.S. Cr. 8vo. pp. 415. (London : 

 Longmans, Green, and Co., 1887.) 



It is a difficult matter to produce a text-book of materia 

 medica which shall answer the requirements of the 

 student in these days. No subject is less clearly defined 

 either by teachers or by the authorities at Examining 

 Boards. Prof. Bentley indicates this difficulty in his 

 introduction, where he first defines "materia medica" 

 and the allied words "pharmacology" and ''therapeutics," 

 and then confesses that our first English authority in this 

 department of science. Dr. Lauder Brunton, has used 

 some of the terms in a different sense. There is one 

 advantage, however, in this difference of view — namely, a 

 variety in the treatment of the subject ; and we have to 

 thank Prof. Bentley for having produced a work which 

 departs in many directions from the somewhat stereotyped 

 arrangement of English works on materia medica. 



As might have been expected from the accomplished 

 Professor of Botany in King's College, the work is mainly 

 devoted to a careful description of the characters of 

 medicinal plants and their products. The arrangement 

 of the plants is founded, so far as the Phanerogamia are 

 concerned, upon that adopted by Bentham and Hooker 

 in their " Genera Plantarum." The descriptions are given 

 very fully, so as to enable the student to recognize the 

 drugs with facility and certainty, and thus at the same 

 time readily to detect any adulteration. The author is 

 right when he expresses his belief that in the latter respect 

 the book will be especially valuable to the pharmacist. 

 To the medical student and to the medical practitioner 

 adulteration is no longer a subject of direct interest. The 

 day has gone by when crude drugs came into the dis- 

 pensary of the doctor, who now buys all the preparations 

 ready made ; and the Examining Bodies, aware of this, 

 have relieved medical students of the laborious subject of 

 drug adulteration, and now require of them the recognition 

 of but a few of the most important specimens. No doubt 

 the book will find its largest circle of readers amongst 

 young men preparing for the examinations of the Pharma- 

 ceutical Society. 



In our opinion it would have been better to give 

 the strength as well as the dose of the more important 

 preparations, such as those of opium. 



The sections on the chemical composition of drugs have 



' "Of course the reformer may write "creatoiote" if hi choojes; bul 

 ''creasote" is inadmissible. 



