LITERATrh'K OF Tllh: M/('R()S('()I'K 213 



incasurcmeiii.s of I lie lij;li( ;il :ill i);irts of Uic spectrum for 

 each of a hundred or so definite color filters, made of dyes 

 in gelatin cemented between optical glass. 



Other Literature. — The catalogues and leaflets issued 

 by the different leading opticians often contain new and 

 useful information, especially those of Zeiss, and also 

 Watson's Microscope Record. Yon Rohr has written good 

 popular descriptions of binoculars (108), spectacles (107), 

 etc. These are especially strong on the historical side. 



Practical Points 



1. The Zeitschrift fuer wissenschaftliche Mikroskopie, the Jour- 

 nal of the Royal Microscopical Society and Watson's Micro- 

 scope Record, are probably the most useful periodicals. 



2. For beginners, Gage's book on the microscope is well 

 adapted. 



3. For high-power microscopy, Coles's "Critical Microscopy " 

 is quite suitable. 



4. For the theory of the microscope, the first volume of Abbe's 

 collected papers is inspiring. 



5. Excellent practical papers on microscopical details have 

 also been written by Nelson (101), Hartridge (71), Coles (47), 

 Ainslie (20, 21), Beck (29, 32), Siedentopf (121, 122), Koehler 

 (82, 83, 85), Mees (95), Metz (97), Berek (38), and Jentzsch (76, 

 77). 



