XXIII, 2. II üb er: Method of preparing large Numbers of Sections. 195 



proven more satisfactory than the otlier metliods recommended ;. 

 Heidenhain's iron - hematoxylin method and Weigert's differential 

 elastic tissue stain and other staining metliods whicli need not be 

 especially enumerated. In staining tlie films of sections the entire 

 fihri is transferred from one fluid to the other by grasping the film 

 with forceps by two corners. Tlie films of sections are, after staining, 

 dehydrated in QQ^Iq alcohol and cleared in carbol-xylol. They are, 

 however, not materially affected by a short stay in absolute alcohol 

 and may then be transferred to xylol. For cutting up the films so 

 that Single sections or small groups of sections may be given out 

 to the individuals of a class it has been found expedient to make 

 use of a small Instrument known as a paper-cutter and shown in 

 fig. 2. This consists of a wheel made of well tempered steel measuring 

 5 cm in diameter with sharpened edge, revolving on an axis and 

 fastened to a handle. In order to cut the photoxylin films, these 

 are brought from the carbol-xylol or xylol used for Clearing onto a 

 dry glass-plate. If necessary, the film is flattened out by brushing 

 over it with a camel's hair brush moistened in carbol-xylol or xylol. 

 The cutting wheel is then run between the rows of sections and the 

 individual sections of the rows. When cut the sections are brushed 

 into a small dish containing the Clearing fluid used. Scissors may 

 be used for cutting the films as desired ; with the method here 

 described the cutting may be , however , much more quickly ac- 

 complished. 



Storing the films of sections. In cutting serial sections on 

 an automatic rotary microtome of any given tissue or organ many 

 more' sections than are necessary for immediate use may be made 

 in a Short time. The entire series may in a comparatively short 

 time be fastened to glass - plates, especially if the sugar-dextrin So- 

 lution is added to the distilled water which is warmed to flatten 

 the sections, as described, and the sections may be made to adhere 

 to photoxylin films without the consumption of much time. Thus 

 an entire series of sections of a given tissue or organ numbering 

 several hundred may be cut and fixed to photoxylin films in several 

 hours , many more sections than generally necessary for immediate 

 use. It has been found convenient to störe for future use the 

 photoxylin films not used in the following way ; after coating a plate 

 with photoxylin and cutting along the edges as has been described, 

 the plate is placed in distilled water and after a few moments is 

 brushed over with a camel's hair brush, this to remove the small 



13* 



