408 



NOTICES OF NEW BOOKS. 



introduction, which reads: "In addition to these methods of investi- 

 gation extensive microscopical examinations of the tissues were carried 

 on," etc. As microscopists we would implore Dr. Casey Wood to supply 

 the only important omission in the present volume by providing us with a 

 companion volume detailing his microscopical researches. J. E. 



Methods in Practical Petrology. By Milner and Part. Cambridge : 

 W. Heffer and Sons, Ltd. Price 2s. %d. 



An addition to the scanty literature of Petrology is always welcome, 

 and a concise account of practical work is sure to find readers desirous 

 of obtaining hints to help them in the rather difficult task of preparing 

 and examining rock-sectiouR, both macroscopically and microscopically. 



AualyBer 

 : fitted over 

 lens. 



Glass plate covering 



stage. 



Polarizer. 



Mirror. 



The present manual is divided into four chapters (each with appro- 

 priate sub-sections'), dealing with : — 1. The preparation of rock-slices. 

 2. Examination of rock-slices. 3. Microchemical methods (staining). 

 4. Mounting of sands and crushed rock material. There is also an 

 appendix dealing with the preparation of stains, and a satisfactory index. 

 A commendable feature throughout the book is the number of footnotes 

 referring the student to standard authors and to a variety of memoirs. 

 These taken altogether form a quite considerable bibliography. 



Several clearly-drawn line-diagrams are included in the text, of 

 which the first (reproduced) is of special interest to microscopists. As 

 will be seen, it is a simple polarizing stand, arranged after the manner of 

 a dissecting microscope, fo(uissing beino- effected by sliding the arm 

 carrying the lens aud analyser up or down the pillar. 



