BAUSCH & LOMB 

 Projection Apparatus 



The most complete lecture room projector 

 ever produced. Lantern slides and micro- 

 scopic objects shown consecutively without 

 change of light or recentering. 



Catalog C on request. 



BAUSCH & LOMB OPTICAL CO. 



Manufacturers 



Microscopes, Photographic Lenses and Shut- 

 ters, Eyeglass Lenses, Fiedl Glasses, etc. 



ROCHESTER, N. Y. 

 New York Chicago 



Boston San Francisco 



Frankfurt a/M Germany 



STANDARD' 



OF 

 QUALITY. 



QUALITY 



VS. 

 -QUANTITY. 



CANDIES, 



COCOA AND 



CHOCOLATES. 



ONE REASON WHY<e%LX^ PRODUCTS 



MAINTAIN THEIR POPULARITY WITH THOSE 



WHO DEMANDTHE BEST GOODS IS THAT 



*&kiV&ri/ STANDARD OF QUALITY 



IS NEVER LOWERED 

 IN ORDER TO JOIN THE RACE FOR QUANTITY. 



HETHODS IN PLANT HISTOLOGY 



Second Edition, Illustrated. Just Published. 



By CHARLES J. CHAFIBERLAIN, Instructor in Botany in the University of Chicago. 



The only book giving full directions for the collection and preparation of botanical material 

 for the microscope. The new and enlarged edition includes chapters on the Venetian turpentine 

 method, microchemical tests, free-hand sectioning, the use of the microscope, and the securing of 

 reproductive phases in the simpler forms of plant life. The book is indispensable for college 

 classes and will prove useful also to high-school teachers and amateurs. 



x + 262 pp., 8vo, cloth ; net, $2.25 ; postpaid, $2.39 



A LABORATORY GUIDE IN BACTERIOLOGY 



For Students, Teachers and Practitioners. Illustrated. 



By PAUL Q. HEINEHANN, Fellow in Bacteriology, The University of Chicago. 



The directions are so full and clear as to offer no difficulty to those unacquainted with labora- 

 tory methods. The course as outlined includes all well-known pathogenic bacteria, as well a» 

 methods for routine examination of air, water and milk, with practical dilution tables, appli- 

 cable also to serum work. The chapter treating of yeasts, molds, and torulae enables the in- 

 structor to select material for non-medical courses. There is also a list of recipes for special 

 culture media. 



" Undoubtedly any student who worked through this laboratory course would have a Tery 

 8»und practical knowledge of the subject." — The Lancet (London). 



vii+ 143pp., 12mo, cloth; net, $1.50 ; postpaid, $1.81 



THE UNIVERSITY OF CHICAGO PRESS 



Address Department 33. 



CHICAGO and NEW YORK. 



