88 Scientific Intelligence. 



to construct his own private cyclopaedia, so to speak, and which, 

 by indicating the best methods of research and bibliographical 

 work, shall keep the investigator in touch with every part of the 

 field. Such a guide requires for its preparation not only a wide 

 acquaintance with the subject and its allied topics, but also a 

 remarkable power of selection by which only the best types for 

 illustration shall be chosen. Without this sense of perspective 

 and proportion, an author will give us an unsatisfactoiy guide, 

 disappointing at every stage. For instance, in the fields occupied 

 by raw commercial products there are many extremely diversified 

 subjects, such as vegetable fibers. These fibers are numbered by 

 the hundred. Among them are a few which have a commanding 

 position on account of their wide use, and these are fully described 

 in every work of reference. Of the remainder, there are some 

 which cannot be referred to any of the great types, and these 

 puzzling cases are likely to be the first ones which come in the 

 observer's path. But if in the hand-book there has been de- 

 scribed a type nearly allied to the one in hand, most of the diffi- 

 culty vanishes. Dr. Hanausek has been very discriminating in the 

 selection of his types and their striking variants, so that his work 

 is of great value. We could wish that in some cases more space 

 had been given to some of the more important subjects of inter- 

 est in this country, for example the species of woods employed 

 in our vast industries of mechanical and chemical wood-pulp 

 manufacture. Certainly more space could have been advanta- 

 geously given to the spruces. But on the whole, the selection has 

 been admirable and the technical treatment very satisfactory. The 

 translation is good throughout, and wholly free from obscurities. 

 It remains to say that the index is copious and helpful, placing 

 within easy reach of the student the immense mass of useful mate- 

 rial contained in the 448 pages. The treatise is a distinct addi- 

 tion to the list of helpful guides in applied Botany and, we maj r 

 add, in applied Zoology. G. l. g. 



2. Lehrbuch der MiJcroskopischen Technik ; von Bebnhard 

 Rawitz. Pp.438. Leipzig, 1907 (WilhelmEngelmann). — Nearly 

 every advance in biological knowledge at the present day is depend- 

 ent upon the ability of the investigator either to make use of the 

 complicated technique which has been developed in the biological 

 laboratory or to devise new and improved methods for himself. 

 Each line of investigation requiring the use of the microscope neces- 

 sitates a knowledge of the special methods by which the particular 

 object to be studied is best prepared for miscroscopical inves- 

 tigation. Descriptions of these methods as they have been 

 employed or devised by the most successful investigators have 

 been brought together in this book, and are presented to the 

 reader in systematic arrangement. Although by no means 

 supplanting the works of Fol, Lee and Mayer, Rothig, Fischer, 

 and others, yet each succeeding year brings some improvements 

 on so many of the older methods that a work of this sort is quickly 

 out of date. The present book is so thoroughly up with the times 



