Preparation and Mounting of Vegetable Tissues 185 



white dish or saucer, select and cut off the portion that is 

 to be mounted, and place it on a slide slightly warmed, 

 drain away as much water as possible, and apply some 

 glycerine jelly ; then, if necessary, lay or spread out the 

 leaves or filaments with a needle and apply the cover-glass, 

 allow the slide to cool, remove the excess of jelly around 

 the edge of the cover, wash the slide in water, dry, and 

 add several coats of enamel or varnish. 



Corallines, whose tissues are hard and opaque, may be 

 cleaned by soaking for a short time in a weak solution of 

 hydrochloric acid, then wash well in water, and mount in 

 glycerine jelly. 



LESSON IX. 



CUTTING, GRINDING, AND MOUNTING SEC- 

 TIONS OF HARD TISSUES. PREPARING 

 METAL SPECIMENS. 



Bone. — Take the femur of a dog or cat, remove as much 

 of the muscle as possible, and macerate in water until quite 

 clean, then allow it to dry. 



(1) With a fine saw make transverse and longitudinal 

 sections. 



(2) Take a hone (water of Ayr stone), moisten it with 

 water, and rub one side of the section upon it until it is 

 quite flat and smooth. 



(3) Wash in water, and set aside until quite dry. 



(4) Take some dried Canada balsam, place a piece on a 

 square glass, and warm gently over a lamp until the balsam 

 melts ; allow it to cool a little, and then press the smooth 

 side of the section into it, and set aside until cold. 



(5) With a fine file rub the section down as thinly as 

 possible. 



(6) Take the hone again and grind the section down 

 until thin enough, using plenty of water. 



(7) Place it, with the glass, in methylated spirit until the 



