174 



NATURE 



[June 25, 1903 



herd, sheep, crops, the latter account being occasion- 

 ally specialised for a few years in order to ascer- 

 tain whether a particular crop or field is paying 

 its way. But we commend to the teachers of book- 

 keeping in such of our agricultural colleges as posses? 

 a farm the problem of devising with an open mind 

 an improved system of farm accounts, which shall be 

 simple, actual, and helpful. 



OUR BOOK SHELF. 



The RSle of Diffusion and Osmotic Pressure in Plants. 

 By B. E. Livingston. Pp. xiii+149. (The Univer- 

 sity of Chicago Press, 1903.) 



Biologists who attach importance to the bearing of 

 physics on their science must be gratified with the in- 

 creasing number of books now appearing on such sub- 

 jects as are treated in the book before us. 



Mr. Livingston's short book is clear and readable, 

 and contains a simple and concise sketch of much of the 

 physics of diffusion and solution. The matter is well 

 put, and difficulties are avoided. But concise treat- 

 ment has its disadvantages, and, in one or two places, 

 a false conception might be obtained from the author's 

 descriptions. Thus there are notable exceptions to the 

 rule that the particles of substances are brought closer 

 together during the change from the liquid to the 

 solid state. And it is scarcely fair to assume that the 

 greater closeness of the particles is the cause of the 

 greater rigidity of solids. 



The limited space available in the book has apparently 

 led to the exclusion of matter which it would be essential 

 for the biologist to be acquainted with, and he should 

 supplement it with the study of some text-book of 

 physical chemistry. With regard to recent work, it 

 must be regarded as unfortunate that the writer leaves 

 out all mention of Brown and Escombe's work on dif- 

 fusion through perforated septa from the physical part 

 of the book, while in part ii., on physiological consider- 

 ations, this investigation receives a bare mention by 

 name in a small footnote. One would have thought 

 that these authors' results would have been fully dis- 

 cussed as having a most Intimate connection with the 

 subject, and as bringing a completely new light to bear 

 on our ideas of the diffusion of gases and of dissolved 

 substances in plants. 



The chapter on the terminology applied to solutions 

 of different concentrations is very lucid, and should 

 prove most useful to biologists. 



In part ii. an account of turgidity and of absorption 

 and transmission of dissolved substances in plants is 

 given. Much information is imparted in a small space 

 considering how nebulous are our ideas on the actual 

 part played by the vital osmotic membranes of plants. 



In the reviewer's opinion, far too much weight is 

 accorded to Wester meier's and Godlewski's hypothesis 

 explaining the ascent of water in trees. These writers 

 assumed that the elevating force is to be found in the 

 exudation pressure of the cells of the wood, cortex, and 

 medullary rays. The physical relations of these cells 

 to the water capillaries of the plant render the idea that 

 the cells at different levels act as relay pumps im- 

 possible. 



The theory of a tensile transpiration current is alluded 

 to, but unfortunately it is criticised in the light of Cope- 

 land's undoubtedly misleading experiment. 



The later chapters of the book are devoted to the 

 osmotic effects of the medium on plants, and sum- 

 marise most interestingly the recent results of osmotic 

 and chemical fertilisation. H. H. D. 



NO. 1756, VOL. 68] 



Mechanical Refrigeration. By Hal Williams 

 A.M.I.Mech.E., A.M.I. E.E. Pp. xiii + 406. (Lon- 

 don : Whittaker and Co., 1903.) Price los. 6d. 

 This book, which is devoted mainly to practical studv 

 of mechanical refrigeration and cold storage, should 

 have a wide circulation, dealing as it does with a grow- 

 ing industry of which the literature, so far as text- 

 books are concerned, is remarkably scanty. It open> 

 with two chapters on the theory of heat engines and n - 

 frigerating machines. The first of these might well 

 have been omitted, as it merely contains a series oi 

 definitions which can only be intended for a tradi r 

 who is totally ignorant of the elementary theory of heat, 

 and are somewhat apt to convey a wrong impression. 

 The second chapter, on thermodynamics, is carefully 

 worked out, the section dealing with the heat chan.i_;( 

 consequent on the performance of internal work by 

 the fluid being particularly Interesting. A chapter 

 devoted to the history of the subject leads to a short 

 study of the methods of preparing the modern refriger- 

 ants, liquid carbonic acid and ammonia, and a descrip- 

 tion of the more important type of refrigerating 

 machinery. In the latter section the author has con- 

 fined himself to an account of ammorivJ, and carbonic 

 acid plant, and in this, considering the dimensions of 

 the work, he Is undoubtedly justified. Fifty pages 

 of the book deal with the auxiliary plant necessary in 

 a cold storage works. Finally, insulation, ice making, 

 the construction and arrangement of cold storage 

 works, and the application of methods of refrigeration 

 to commercial processes are fully dealt with. The 

 author wisely omits all mention of liquid air and its 

 problematical applications. The book is well illus- 

 trated by means of photographs and diagrams, and 

 the text is clear and concise. M. W. T. 



Oie stammgeschichtliche Entstehung des Bienenstaaies 



sowie Beitrdge zur Lebensweise der solitdren it. 



sozialen Bienen {Hummeln, Meliponinen, 8iC.). 



Herausgegeben von Dr. H. von Buttel-Reepen. 



Pp. xIi-l-138. (Leipzig, 1903.) Price 2.40 marks. 

 This is a book that should not be overlooked by those 

 who are Interested in the many important questions 

 that are opened up by the habits of social Insects. The 

 author points out that the highly developed organisa- 

 tion of the life of the hive-bee does not stand alone, 

 but may be traced up from the commencement of mere 

 association of solitary species, through the less organ- 

 ised communities of humble-bees, &c., to Its perfection 

 in the hive-bee. A great number of outlying questions 

 respecting parasitic bees, wax-secretion, &c. , are also 

 more or less fully discussed. The author is very 

 anxious to eliminate, so far as possible, the natural 

 tendency to anthropomorphlse the actions of bees to 

 too large an extent, and appears to take the view that 

 Inherited tendencies have to a large extent rendered 

 their actions subjective and automatic. The Index Is 

 very full, and Is preceded by a list of nearly 200 books 

 and papers dealing with the subject, which cannot fail 

 to be of great value to any serious student of bee-life. 



The Mind of Man. By Gustav Spiller. Pp. xIv-l-552. 



(London: Swan Sonnenschein and Co,, Ltd.. 



1902.) 

 Mr. Spiller suffers apparently from the constitutional 

 defects of extreme prolixity, and a marked contempt 

 for the views of psychologists who have the misfortune 

 to prove themselves " unscientific " by disagreeing 

 with himself. The reader who Is ready to overlook 

 these deficiencies will find much Interesting discussion 

 of the principal problems of psychology In his book, 

 though scarcely, I think, any considerable fresh con- 

 tributions to the science. The author's fundamental 

 point of view may be indicated by his definition of 



