March i6, 1899] 



NA TURE 



459 



ear and terse exposition of the principles of physical 

 lemistry cannot be too highly commended. The 

 eatment of the subject adopted by the author pre- 

 ripposes a considerable knowledge of chemistry and 

 ^ysics, as well as an elementary acciuaintance with the 

 (fferential and integral calculus. The first instalment, 

 .ere under review, is entitled "Chemical Dynamics," 

 .id will be followed by other parts dealing with chemical 

 tatics, and the relation between properties and chemical 

 pmposition. The distinction made by the author be- 

 j,veen chemical dynamics and chemical statics is similar 

 p that adopted by Lothar Meyer. Under chemical 

 tatics he proposes to deal with theories of the structure 

 f matter, the conceptions of atom and molecule, and 

 ie determination of constitution and configuration. 

 Jnder chemical dynamics he here discusses chemical 

 hange, affinity, velocity of reaction, and chemical 

 quilibrium. 



, Beginning with chemical equilibrium, he treats the 

 ubject first from the thermodynamical standpoint, and 

 hen from the standpoint of the kinetic molecular theory. 

 This dual mode of treatment has many advantages. The 

 itudent is introduced to the study of chemical equilibrium 

 k'ithout being concerned with any hypothesis regarding 

 .he inner mechanism of the systems considered. He is 

 ^nly occupied with the different phases (or mechanically 

 leparable components) involved, and gains the necessary 

 'nsight into the subject through diagrams of volume, 

 Pressure, temperature and concentration, together with 

 pome simple deductions from the fundamental principles 

 jf thermodynamics. Transformation points, vapour 

 aressure, dissociation pressure of solids, and solubility 

 aaturally have their place here, equilibrium for one and 

 two substances being treated at length. Examples are 

 klso given of cases of equilibrium with three and four 

 ^ubstances ; but owing to the multiplicity of phases, the 

 diagrams are necessarily comple.x and rather cumbrous. 

 Dissociation, both gaseous and electrolytic, etherification, 

 equilibrium between electrolytes, hydrolysis, and the 

 lavidity of acids and bases are more conveniently dealt 

 with from the molecular standpoint ; and the section 

 concludes with general considerations as to the effect of 

 pressure and temperature on chemical equilibrium. 



The velocity of chemical action is naturally also treated 

 from the kinetic point of view, and first the author gives 

 a theoretical discussion of the subject, exhibiting the 

 nature of uni-, bi-, and trimolecular reactions, the relation 

 of velocity constants to equilibrium constants, the method 

 jfor determining the number of molecules taking part in a. 

 \ chemical action, and the nature of the retarding influences 

 'at work. Then follows a selection of representative 

 'empirical results regarding the influence of the medium, 

 I temperature, and pressure on the reaction velocity. 

 ' Finally, an account is given of the progress of the re- 

 action wave, and in particular of the explosion wave. 

 j The translation is well done, and will probably appeal 

 ( more to English readers than the original. One or two 

 I slips which appear in the German edition might have 



ibeen corrected in the French version ; e.g. in the 

 pressure-temperature diagram of sulphur. Fig. 9, the 

 line KF should slope upwards and away from the 

 j pressure axis instead of towards it, and at p. 66, line 10, 

 I tension should obviously be temperature. J. W. 



NO. 1533, VOL. 59] 



THE CULTIVATION OF BERRIES. 

 Bush Fruits. By Fred. W. Card. Pp. xii -F 537 ; 113 



illustrations. (New York : the Macmillan Company. 



London : Macmillan and Co., Ltd., 1898.) 

 ' I ■'HIS is in more senses than one a remarkable book. 

 -•- The title-page tells us that it is a " Horticultural 

 monograph of raspberries, blackberries, dewberries, 

 currants and other shrub like-fruits " {sic). The preface 

 tells us that the book " is an extension of a thesis pre- 

 sented to the Cornell University for the degree of Master 

 in Science in Agriculture." It is hard to imagine any 

 university in this country recognising a thesis on the art 

 of growing gooseberries and currants ! Yet that the 

 subject is capable of scientific treatment is evidenced by 

 the volume before us. The aim is " to treat general 

 truths and principles rather than mere details of 

 practice. A book cannot instruct in all the details of 

 any rural business because these details vary with the 

 environment and personality of the operator. The book 

 should attempt, therefore, to give such instruction as to' 

 enable the reader to think out and to solve the local 

 problems for himself 



The first part is devoted to general considerations 

 concerning the situation and management of a fruit 

 plantation. In the second part the brambles, raspberries, 

 blackberries, and similar fruits are considered in detail, 

 and in a manner utterly different from what we should 

 expect in a graduation thesis. 



Part iii. is similarly devoted to " Groselles," a word 

 invented by the author to include both gooseberries and 

 currants. Here we find the same minuteness of detail 

 and accumulation of facts as in the other portions of 

 the volume. 



The fruits enumerated are mostly of American 

 origin and of recent development, and they illustrate in 

 a very striking way the enormous strides which our 

 American cousins are making in all matters relating to 

 the cultivation, the packing, " canning " and marketing of 

 fruits. They show a fertility of invention, a readiness to 

 adopt new procedures, and to avail themselves of oppor- 

 tunities to a degree which we look in vain for on this side 

 of the Atlantic. In the matter of climatal conditions the 

 United States have, so far as these particular fruits are 

 concerned, no advantage over the mother country. 

 Already we have American cranberries exposed for sale 

 in every grocer's shop in the kingdom, whilst we do not 

 suppose that the whole available area in Ireland, Wales 

 or Scotland sends to market a week's supply. 



A curious circumstance to be noted about the fruits 

 which form the staple of this volume is that they are 

 mostly of American origin. British gooseberries or 

 European currants do not, as a rule, thrive in the States, 

 or, rather, they cannot so well resist the attacks of the 

 mildews and moulds as the bushes of native origin do, 

 and consequently the English varieties go out of culti- 

 vation as less fitted to the environment than the native 

 varieties. 



Another point to be noted is the comparatively recent 

 origin of these varieties. Our gooseberries and currants 

 represent the selection that has been going on here for 

 ages, and as we rarely if ever see any advance in these 

 fruits nowadays, but only a kaleidoscopic shifting of old 



