Cutting, Staining, and Mounting Vegetable Sectioiis 169 



they bend and become fixed by the action of the spirit, 

 and will not then stand the slight pressure required to 

 hold them firmly between the carrot without cracking. 

 When this happens, soak the leaf in warm water until it is 

 quite pliable ; it can then be embedded in carrot without 

 any risk of being broken. Stems and petioles of many 

 palms are naturally too hard, and they may contain a large 

 amount of silica. They must be soaked in water for a while ; 

 then transfer to liq. potassse for from one to twelve hours. 

 Wash again well in water to remove all trace of potash, then 

 reharden in methylated spirit. The shells of many stone 

 fruits may be softened and cut by this method. 



Section-cutting, by hand and with a microtome, should 

 be done in the same manner as described in Lesson II. 



Bleaching. — Vegetable sections generally require bleach- 

 ing before they can be properly stained. Chlorinated soda 

 is used for this purpose. Take of dry chloride of lime 

 2 ounces, of washing soda 4 ounces, and distilled water 

 2 pints. Mix the lime in 1 pint of the water and dissolve 

 the soda in the other. Mix the two solutions together, 

 shake well, and let the mixture stand for twenty-four hours. 

 Pour off the clear fluid, filter, and keep in a stoppered bottle 

 in a dark place, or cover the bottle with paper. Soak the 

 sections in distilled water. Pour off the water and add a 

 quantity of bleaching fluid. Allow this to act for from 

 one to twelve hours. Wash well in water, which must be 

 changed several times to remove all traces of soda. The 

 sections may now be stained, or they may be preserved in 

 spirit until required. 



Staining Borax Carmine (suitable for ovaries, fruits, 

 etc.). — Pure carmine 1 dram, liq. ammonias fort. 2 drams. 

 Dissolve the carmine in the ammonia, and add 12 ounces 

 of a saturated solution of borax in distilled water. Filter 

 and keep in a stoppered bottle. 



(1) Put some stain in a watch-glass, and immerse the 

 section for three to five minutes. 



(2) Wash well in methylated spirit. 



