THE AMERICAN MONTHLY 



[Mar., 



section will adhere firmly through turpentine, alcohol and aque- 

 ous dyes, staining is in no wise interfered with. 



Pr. Alleger recently informed us that since the happy thought 

 of using formalin to render gelatine fixative insoluble occurred 

 to him he has discarded all other fixatives using this both for 

 individual and cla-ss work an I that during the entire work of 

 the session just drawing to a close, neither he nor an}' member 

 of his class has had a section thus fastened to the slide slip or 

 become detached in the ordinary process of staining. Nothing 

 less than a stream of water or other mechanical means being suf- 

 ficient to loosen a section when thus (properl}') fixed. This is a 

 result he has been unable to secure in any other manner and 

 is regarded as suppl^'ing a long felt want. 



MICROSCOPICAL APPARATUS. 



Price of Zeiss's Objectives. — The following announce- 

 ment has just been received : 



Having, through nearly ten years practice, gained a greater 

 experience in the production of the apochromats, and having 

 recently succeeded in materially simplifying the construction 

 of these lenses, we have been permitted to make a considerable 

 reduction in their prices. 



LIST OF THE APOCHROMATIC OBJECTIVES. 



*The three objectives 24 ram, 12 mm and 6 mm of the dry series are con- 

 structed exclusively for the 10-inch tube ; all the others are adjusted either 

 for Continental or English tube. f With correction collar. 



