HISTOLOGICAL METHODS. 



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plug (K, Fig. 5 9), capable of being moved up or down by 

 means of a screw (D). The tissue to be frozen is placed in 

 the well, and sections are made by gliding a knife through 

 the tissue that projects above the level of the brass table. 



FIG. 59. Vertical section of freezing microtome. R, Transverse section of the 

 knife employed. 



The thickness of the sections is regulated by an indicator 

 (E). A freezing mixture is placed in the box (c), the water 

 from which flows away by the tube (H). The microtome 

 is clamped to a table by the screw (F). The tissue is seen 

 in A, Fig. 59, and the freezing mixture in G of the same 

 figure. In the instruments now made, the brass box is 

 covered with gutta-percha. 



The freezing microtome is essentially the well-known 

 microtome devised by Mr. Stirling, Sub-Curator of the Ana- 

 tomical Museum of the University of Edinburgh, modified 

 for freezing. It serves a double purpose, i. It serves the 

 same purpose as the microtome of which it is a modifica- 

 tion ; that is to say, it may be used for cutting unfrozen tissues 

 imbedded in paraffin in the usual way. 2. For cutting 

 tissues hardened by freezing. The second method of using 



