260 THE AMERICAN MONTHLY [Aug 



of Zeiss, Leitz, and Reichert. A great many slides are in- 

 cluded. This firm has a slide-lending- department. A no- 

 ticeable feature is an exceptionally complete series of rea- 

 gents and stains prepared by the most scientific methods. 

 There is a special catalogue of the necessary apparatus for 

 the study of the effects of malaria upon the blood, bacteri- 

 ological outfits, etc. The preface states that microscopes 

 are included that are suitable for engineering, brewing, 

 baking, paper-making, and other industries. 



Micro-organisms. — The Microscopy of Drinking Water, 

 by G. C. Whipple, is published by John Wiley & Sons. 

 While the importance of the chemical and bacteriologi- 

 cal analysis of water has long been recognized, the study 

 of the lower forms of animal life included under the term 

 "microscopy of water" has received far too scant atten- 

 tion as a branch of hygiene. It is beginning to appear 

 that quite as accurate estimates of the purity of drinking 

 water may be based upon its microscopy as upon the some- 

 what uncertain and more laborious results of chemical 

 and bacteriological analysis. On this account the appear- 

 ance of an elementary work upon the forms of animal life 

 commonly found in drinking water, and the significance 

 attaching to their presence, is most acceptable to a large 

 class of readers who are brought in contact with this sub- 

 ject. The present volume is specially adapted to the needs 

 of the medical profession, as the practical use of the data 

 presented requires only a moderate biological training. 

 The first half of the work contains a great deal of useful 

 information regarding the objects and method of micro- 

 scopical examination of water, the factors governing the 

 appearance of micro-organisms in water, the origin and 

 significance of odors in water, and the method of storing 

 surface water. The remaining chapters are devoted to an 

 elementary description of the principal genera of micro- 

 organisms, beautifully illustrated by twenty-nine full-page, 

 half-tone pictures. The volume will fully repay careful 

 reading, is sufficiently complete for an elementary book of 

 reference, and should find a place in every medical library. 



