SEI'Tli.MBER 20, 1894] 



NA TURE 



495 



The influences which in Germanv have led to so wide- 



(spread and successful prosecution of research in organic 

 chemistry are traceable partly to the university system, 

 jwhich demands the production of a piece of original 

 :\vork, and partly to the wonderful development in that 

 irountry of the colour industry, which is now practically a 

 German monopoly. We have, however, British chemists 

 'who have successfully devoted themselves to " organic " 

 chemistry, and among them the names of Parkin (son as 

 veil as father) and Kipping stand out in honourable 

 prominence. Hence a te\t-book issued in these conjoint 

 inames would naturally excite attention and interest. 

 I " Our original intention," say the authors in their pre- 

 face, " was to write a small text-book on organic 

 :hemistry, based on the syllabus drawn up by the Science 

 ind Art Department." .Such a plan, however, was not 

 ivorthy of the reputation of the writers, and they are to 

 :)e congratulated upon having enlarged the scope of their 

 .vork beyond this rather narrow limit. 



This volume, Part I., deals with the fatty compounds, 

 md "contains in the first place a general account of the 

 nethods most frequently employed in the separation, 

 jurification, and analysis of organic compounds, and in 

 he determination of molecular weight. The preparation 

 md properties of typical compounds are then described, 

 ittention being directed to those changes which come 

 mder the heading of general reactions rather than to 

 solated facts regarding particular substances. Ques- 

 ions of constitution are also discussed at some length, 



1 in the case of the most typical compounds, the 

 I ;s on which the given constitutional formula is based 

 re specifically mentioned." From this outline it will be 

 een that the arrangement of the book is not essentially 

 Kv. el. The best feature is the discussion of the struc- 

 ure or constitution as e.xpressed by the formuKv; of the 

 nore important compounds, and, notwithstanding one 

 ■ r two statements which look rather dogmatic, this is 

 l.e feature which gives it some superiority over other 

 e.xt-books of about the same dimensions. No reference 

 s made in this volume to ideas of geometrical isomerism, 

 hich are prudently reserved for the second part. It is 

 o be regretted that the authors should have allowed 

 hemselves to drop, in print, into the slovenly phrase- 

 logy which is too common among all classes of chemists, 

 "or example, p. 99, cane sugar is said to be converted 

 iito "equal molecules" of dextrose and levulose. It 

 5 true that this expression is employed by writers of 

 igger books, but that is no justification for the con- 

 inuance of a phrase which is absolutely unmeaning. 

 )n p. 204, triethylamine is said to be "a stronger 

 lase" than diethylamine ; while on the opposite page, 

 03, tetrethylammonium hydroxide is stated to be "a 

 tronger base" than potash or soda. If eminent 

 hemists occupying the position of university professors 

 re so lax, it is not to be wondered at that the poor 

 iouth Kensington teacher and his pupils should be 

 ometimes found wanting when called upon for 

 lefinitions. 



Chapter xiii., p. 218, opens with this stateinent : — 



" It may be assumed as a general rule that the changes 

 fhich any particular group of atoms is capable of under- 

 ;oing are independent of the nature of the groups with 

 vhich it is combined." 



NO. 1299, VOL. 50] 



This requires for its justification something more than 

 the example which follows, for organic chemistry is full 

 of instances of the influence which neighbouring atoms 

 and groups have upon the character of a given atom or 

 group ; and at the top of the very same page the authors 

 draw attention to one of these, namely : '• The influence 

 of alkyl groups in increasing the basic character of an 

 element." Mercury is here referred to, and the meaning 

 is obvious to the instructed chemical reader, though the 

 reference to the basic character of the element, coupled 

 with the succeeding statement that mercuric oxide is a 

 feeble base, is well calculated to confuse the mind of a 

 learner. 



Dr. Turpin's book is one of the series of science 

 class-books adapted to the elementary stage of the 

 South Kensington syllabus, and issued by Macmillan. 

 Here again the arrangement runs upon well-established 

 lines, beginning with processes of analysis, methods of 

 estimating molecular weight, and then plunging into the 

 successive series of hydrocarbons, alcohols, ethers, 

 acids, and so forth. Detailed directions are given for 

 the performance of a selection of instructive experi- 

 ments, the number of which, however, being no 

 more than twenty in the whole book, ought to be 

 considerably increased. At the end of each chapter 

 are some questions which will doubtless be sug- 

 gestive to both pupil and teacher. These are good 

 and useful features of the book, which it must be re- 

 membered is labelled elementary ; but, oh ! Dr. Turpin, 

 where in the whole range of stereo-chemical literature 

 did you find the " valuable hypothesis '' that '" the carbon 

 atom is regarded as being similar in shape to a regular 

 tetrahedron".' (p. 31). We certainly feel justified in 

 protesting against the author's treatment of the "tetra- 

 hedral theory of the carbon atom," which is disposed of 

 in about twenty lines with three shaded diagrams. It 

 is more than doubtful whether this hypothesis should 

 appear in an elementary book at all, but to thrust it in 

 without reference to the sort of fact which it is intended 

 to explain, and to state it in this crude form, cannot be 

 too strongly condemned. 



Both these little books have theirgood points, and both 

 will undoubtedlybc found useful by many young students ; 

 but the perusal of them and others leaves the impression 

 that the text-book which will meet all the difficulties and 

 provide fully for the needs of the student entering upon 

 this ever-widening subject of organic chemistry, has yet 

 to be written. Organic chemistry is not begun till the 

 student has some acquaintance with inorganic and 

 general chemistry, and if properly taught previously he 

 ought not to require to be told how to deduce a formula 

 from the results of analysis, or how to determine a 

 molecular weight. The practice of reserving these 

 matters as an introduction to organic chemistry belongs 

 to a bygone time, and it has the disadvantage of leading 

 many students to think that vapour density and other 

 methods are applicable only to organic compounds. The 

 arrangement of carbon compounds in homologous series 

 from the outset is also confusing to the beginner, because 

 each succeeding term of such a series is derived from 

 distinct materials which have no apparent connection 

 with either those which go before or those which follow 

 after. .V better plan, adopted in seme of the older books, 



