4IO 



NA TURE 



[March i, 1894 



discovery has given such a wonderful impulse, is of course 

 not only justifiable, but highly necessary at the present 

 stage. It is not to this, nor to the matter of the book gene- 

 rally, which indeed is admirably selected, that we venture 

 to take objection, but rather to the method of treatment. 

 The method adopted in the general part is not calculated 

 in our opinion to present a history of the development of 

 the subject in a striking and lucid manner. The chapter 

 really consists of a series of abstracts of memoirs, 

 -anting over the whole field of stereochemistry, placed in 

 chrcrnological order of publication, to which the author 

 seldom adds expository or critical remarks. The paucity 

 of experimental facts in illustration of the theories 

 described, adds still further to the unattractiveness of 

 the pic:ure. The author, it is true, expressly states in 

 the preface that details have been intentionally omitted, 

 but the unavoidable result is that the abstracts are in 

 many cases so bald as to be shorn of much of their interest, 

 and the often repeated reference to the special part for 

 application of the theories described becomes tantalising. 

 Stereochemistry has already in the short period of its 

 existence pushed its way in so many different directions, 

 that to present an effective picture of its growth, it would 

 be necessary to trace its development along a number of 

 more or less independent lines. The opening chapter of 

 the special part, we ought to state, supplies this want to 

 a great extent with respect to optical isomerism, and 

 similar sketches will, no doubt, be given in the other 

 subdivisions. 



The idea that the relative position of atoms in space 

 within the molecule, must be an important factor in de- 

 termining the properties of compounds, was, no doubt, 

 present to the minds of many of the founders of the 

 atomic theory, and it is interesting to learn from a 

 correspondent in these columns (vol. xlix. p. 173) that 

 Wollaston had a very clear conception of this fact. The 

 history of stereochemistry, however, begins with Pasteur, 

 and we are glad to see that the importance of his ex- 

 perimental discoveries and far-seeing predictions receive 

 ample recognition. A portrait of the veteran chemist is 

 placed opposite the title-page, with that of his younger 

 colleagues, Van't Hoff and Le Bel. 



As is generally known, these two distinguished chemists 

 arrived at their fruitful theory of the asymmetric carbon 

 atom by two entirely different paths, and their positions 

 with respect to it are by no means identical ; indeed, Le 

 Bel has entered a protest on several occasions against 

 his views being confounded with those of Van't Hoff. 

 The disadvantage of the chronological method, to which 

 we have alluded, is very apparent here, for to form any 

 adequate idea of Le Bel's present stand-point, the reader 

 has to hunt up the summaries of various papers which 

 are scattered throughout the general and special parts. 

 The views held by Le Bel are particularly interesting-, as 

 they lead him to sundry fundamental conclusions, which 

 must seem very heretical to those who have adopted the 

 doctrine of Van't HofF without qualification into their 

 chemical creed. Thus he has recently concluded that 

 even a molecule of the type CR4 does not necessarily 

 possess a configuration which can he symbolised by a 

 regular tetrahedron, and that the usually accepted argu- 

 ment for the symmetrical distribution of the four hydrogen 

 atoms in the molecule of marsh gas, based on the exist- 

 NO. 1270, VOL. 49] 



ence of only one monoderivative, is unsound. The 

 experimental ground of his conclusion is the more interest 

 ing, as it furnishes one of the few instances in which the 

 obvious property of the crystalline form of a compound 

 has been used for the purpose of determining its mole- 

 cular configuration. He finds in fact, contrary to 

 Wislicenus' prediction with respect to compounds of 

 the type indicated, that carbon tetrabromide does not 

 crystallise in the regular system. Again, Le Bel's views 

 do not exclude the possibility of optical isomerism in 

 unsaturated bodies, and he finds indeed that solutions of 

 citraconic acid become strongly active when mould is 

 grown in them ; should this discovery prove to be due 

 to the production of an active isomeride of this acid, the 

 discovery would revolutionise an important branch of 

 stereochemical theory. Such considerations remind us 

 that the prevailing stereochemical theories, fruitful as 

 they have been, are nevertheless only a first approxi- 

 mation to the truth, and will have to undergo important 

 modifications with the progress of discovery. 



The reader of Dr. Bischoff's book will find abundant 

 food for reflection in the numerous monographs, of which 

 very good abstracts are given. Many of them, dealing 

 with such fundamental subjects as the nature of chemical 

 affinity, valency, the significance of double and treble 

 linkage, the influence of the form and motion of atoms on 

 chemical action, are highly interesting and suggestive ; 

 some of these papers will be already familiar to the 

 readers of the Berichte and Annalen, but others 

 which have been published in separate form are not 

 readily accessible to the English chemist. The perusal 

 of the opening chapter will convince the reader that 

 stereochemical conceptions are already initiating a 

 searching revision of the very foundations of the chemical 

 edifice, and that they are destined in the near future to 

 play an important, perhaps a predominant, part in the 

 progress of chemical theory. 



■.. We may add that the book is abundantly illustrated 

 with geometrical figures, and that a detailed index is 

 promised with the second volume. 



We have observed the following misprints: "sym- 

 metrischen " instead of " unsymmetrischen" in the last 

 paragraph, p. 24 ; " + " instead of "x," p. 97 ; " Nach- 

 wirkung" instead of " Nahewirkung," p. 121. 



T. P. 



MARINE BOILERS. 



By 



Marine Boiler Management and Cotistruction. 

 C. E. Stromeyer. (London: Longmans, 1893.) 



THE difficulties attending the economic management 

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The author treats in detail the generally accepted 

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 of marine steam generators, and discusses, more or less 

 fully, the causes of corrosion and other sources of wear 

 and tear in boilers. Fuels and the conditions of heat 

 transmission through plates are treated at length, whilst 

 in the latter portion of the book, strength of materials 



