210 THE USE OF THE MICROSCOPE 



microscope, clear enough to be comprehended by any 

 student. It offers a number of practical hints for the 

 beginning microscopist; and also gives abundant details 

 as to the methods and organization of class work in his- 

 tology and microscopical embryology. It gives especially 

 full accounts of illuminating, drawing, and modehng 

 methods. Metzner's 1928 edition of Zimmermann's book 

 on the microscope (98c) contains descriptions of new 

 apparatus and new methods, and general elementary 

 instructions. 



Books on High-power Work. — Of the books which deal 

 with high-power work, Spitta's thick volume (127) gives 

 among other things the results of his experience with photo- 

 graphing diatoms and testing objectives. He was one of the 

 first systematically to employ green glass, and the yellow- 

 green Wratten filters. The book also includes excellent 

 elucidations of the elementary mathematical points of 

 microscopy, often written by Conrady who assisted Spitta 

 more or less. Beck's second volume (33) contains his impor- 

 tant experiments on limiting the size of the source of light, 

 with reference to resolution and glare. There are also many 

 practical hints from the point of view of the manufacturing 

 optician. Coles's ''Critical Microscopy" (46) is mainly a 

 first-hand account of the successful methods of the author, in 

 the microscopy of blood parasites. The methods described 

 are based on E. M. Nelson's many published papers. The 

 book is practical throughout, and the present writer highly 

 recommends it, especially to medical microscopists. Dall- 

 inger's 1901 revision of the first volume of Carpenter's 

 classical microscope book (43) is also partly based on 

 Nelson's practical work, but it is now rather out of date. 

 It contains an exposition of the diffraction theory of the 

 microscope revised by Abbe himself. The most important 

 part is perhaps the full history of the microscope. Metz- 

 ner's recent volume (98c) gives a good account of photog- 

 raphy with the microscope, and discusses various matters 

 relating to high-power work. 



