212 



NA TURE 



[December 24, 1908 



the work involved in the systematic adoption of the 

 anatomical method is so enormous, that it seems 

 hardly likely that great progress will be made in this 

 direction for some time to come. 



The value of chemical substances in the plant is 

 also emphasised for helping to establish points of 

 affinity, though cases do occur in which similar sub- 

 stances of a peculiar nature are found in quite un- 

 related plants. One of the difficulties of the method 

 lies in making the choice of those anatomical charac- 

 ters which may prove to be of systematic importance. 

 It is clear that characters, which are ancestral rather 

 than adaptive, will be of most value from the taxo- 

 nomic point of view. The value of an anatomical 

 character, however, cannot be predicted, and at times 

 exceptions will be found to a character which appears 

 to be otherwise typical of the particular group or 

 order. Much light may be expected to be thrown by 

 the anatomical method as to whether certain features 

 in a plant are to be regarded as ancestral or adaptive 

 from a comparison with other closely allied plants ; 

 and it may be noted in passing that careful work in 

 this direction is being done on the anatomy of seed- 

 lings in this country. K word of warning, however, 

 is necessary, which is not forgotten by the author, 

 to those adopting the method, since it is not yet 

 known whether a given character may be constant in 

 a single spec'es under different conditions of cultiva- 

 tion. The tea-plant, for instance, may or may not 

 possess spicular cells in the leaf. 



Dr. Solereder concludes his excellent and interesting 

 introduction with a summing up of the possibilities of 

 and warnings against the dangers of the anatomical 

 method. It only remains to praise most highly the 

 way in which Messrs. Boodle and Fritsch, under the 

 careful editorship of Dr. Scott, have carried out the 

 very arduous work of translating a volume, every 

 page of which seems scarcely large enough to con- 

 tain the solid and pregnant matter with with it is 

 crowded. 



A word of thanks must be added to Dr. Fritsch for 

 the glossary at the end of the second volume, in 

 which the chief terms used in anatomical description 

 are defined, or a reference to a definite passage in the 

 work is given where such terms are explained. In 

 most cases the German equivalents of the terms are 

 given, making the glossary of considerable value. 



.\. W. H. 



PROBLEMS OF THE PAPER MILL. 

 Chapters on Paper-wakiiif;. ^"ol. v., Concerning the 

 Theory and Practice of Beating. By Clayton 

 Beadle. Pp. vii+:82. (London: Crosby Lock- 

 wood and Son, 1908.) 

 ' I "HIS is a record of observations incidental to an 

 -•- analytical study of the process of " beating " in 

 the paper mills, the process by which the fibrous raw 

 materials are prepared, by wet milling, for the actual 

 IJaper-making operations. The central importance of 

 the beating process is generally recognised ; it is also 

 evident that it is a highly complex operation. Ihe 

 purpose of this volume is to suggest to paper-makers 

 NO. 2043, VOL. 79] 



what are the factors of the result, and how they may 

 be effectually studied by way of observations which 

 can be recorded in terms of numbers. 



The author's observations are in the main those of 

 mechanical energy consumed in the various stages of 

 beating, i.e. in the "breaking in," the "beating" 

 proper, and in " refining." 



Beaters of the various types have been analytically 

 studied, and the results are discussed in reference to 

 the general structural details of the machines them- 

 selves, as well as of the main working parts, that is, 

 the roll and the bed-plate. The main purpose is to 

 establish their relative economy and efficiency. 

 Thus the Hollander is generally contrasted with the 

 more modern types of beaters, e.g. the " Reed," the 

 "Tajdor," and the " Tait engine," and the separated 

 operations of " refining " in such engines as the 

 " Kingsland " or " Jordan." Chapter .x., on " the 

 relative merits of stone and metal beater bars," is a 

 useful contribution to progressive problems. 



The author generally avoids drawing positive conclu- 

 sions in view of the fact that efficiency, or the integral 

 result of the preparation, involves those still obscure 

 factors of condition, that is, the relation determined 

 bet\\-een the beaten fibres and the watery medium in 

 which they are carried in suspension, to be compacted 

 into the wet web on the wire of the paper machine 

 or mould. This is the subject-matter of a special 

 chapter (chapter xvii.), which records the results of 

 experiments in the grading or fractionation of pulps 

 bv drv or wet methods, the former giving results 

 according to dimensions, the latter introducing the 

 complicating factor of " hydration " or " wetness." 



The book is certainly a record of progress in the 

 technology of paper-making. It emphasises the criti- 

 cism which paper-makers make on the realistic tenden- 

 cies of our technical schools. .\ " model " paper- 

 making plant, such as has been installed at the Man- 

 chester School of Technology, is so far illusive in its 

 realism that a " model beater " is not a representa- 

 tion to scale of the working conditions of the ordinary 

 engine ; and as the beating process constitutes the 

 essential preparation of pulps, the educational result 

 of a model mill is weakened by the implication of an 

 incorrect perspective. 



Contrariwise, the author's observations suggest an 

 individuality or idiosyncracy of beating engines, and 

 this degree of unconformity to type entails special 

 study of each machine in work, which study may be 

 purely empirical or may be based upon selective 

 quantitative investigations of the essential factors. 



The technical records of this book are intended to 

 serve as models of such investigations in the mill. 



The educational value of this volume is weakened by 

 its method or want of method. The author trusts his 

 matter to evolve its own logical form and cohesion, 

 wherein he so far abdicates the privileged position of 

 teacher, which is to be didactic even when some risks 

 have to be taken in stating conclusions; this is neces- 

 sary to awaken and sustain (he interest of the 

 student. 



The matter would be much improved by a clear 

 expose of principles, and the contributory factors of 



