PRACTICAL HISTOLOGY. 



Freeziny Fluid. 



Take of the syrup 

 ,, ,, mucilage 

 water 



4 parts. 



5 ' " 



Boil and saturate while hot with boracic acid. Filter through 

 muslin. 



The tissues are soaked for twenty-four hours or longer in this 

 fluid, i.e., after removal of all alcohol from them. The longer they 

 are kept in it the better ; in fact, tissues may be kept permanently 

 ready for freezing in this fluid. 



Rutherford's Ice-Freezing Microtome (fig. 33). By means of a 

 finely-graduated screw a brass plug can be raised or lowered inside. 



FIG. 33. Rutherford's Freezing Microtome adapted for Freezing with Ether. 



a brass cylinder. At the top of this cylinder is a stage or plate (B). 

 The plug has a small flattened brass knob screwed into it, so as to 

 catch the frozen mass, and prevent it from being detached (K). 

 Practically this is the arrangement of the microtome devised by the 

 late A. B. Stirling, curator of the Anatomical Museum of the 

 University of Edinburgh. To this arrangement Professor Ruther- 

 ford added an ice-box (C), which surrounds the upper part of the 



