262 PRACTICAL BOTANY 



a test-tube ; the fluid is then poured off and the residue 

 collected on a filter, and well washed with water; the speci- 

 mens may then be mounted in glycerine. 



Schuize's Solution (see above, Chlor-Zinc-Iodinej. 



Sodium Chloride is used as a 10 per cent, solution, or as a 

 saturated solution in water, as a solvent for proteid-crystalloids. 



A more dilute solution (i 5 per cent.) is used for inducing 

 plasmolysis. 



Sulphuric Acid. This is used either concentrated, or dilute (i to 

 3 of water). It causes, in either case, the swelling up of cellu- 

 lose cell-walls, starch grains, &c. ; when cellulose cell-walls 

 which have been previously saturated with solution of iodine are 

 treated with sulphuric acid, they turn blue. 



Concentrated sulphuric acid dissolves cellulose and starch, 

 but cuticularized or corky cell-walls and the middle lamella of 

 lignified cells resist its action. It is used with cane-sugar, as a 

 test for proteids, and a few drops of it are added to a solution 

 of aniline sulphate as a test for lignin. 



It may also be used as a solvent for crystals of calcium 

 oxalate. 



Turpentine is used with creosote, or carbolic acid, as a clear- 

 ing agent before mounting in Canada balsam. 



Water may be used as a mounting medium, and as a solvent 

 for various reagents ; it may also be used for the cultivation of 

 small organisms, or pollen-grains, spores, or Fungi, under the 

 microscope, and for this purpose a moist chamber is to be con- 

 structed as follows : 



A piece of thick rough cardboard is cut to the size of the 

 glass slide, and a circular hole is punched out of the middle of 

 it of such a size as to be completely covered by a cover-slip. 

 The piece of cardboard is then soaked in water (or boiled in 

 water when pure cultures of Fungi are to be made), so as to 

 saturate it, and placed on the glass slide. A drop of water (or 

 solution as described below) is placed on the cover-slip, the 

 object is immersed in it, and the cover-slip is then inverted over 

 the hole in the piece of cardboard. Thus the object is sus- 

 pended in a drop of liquid on the under surface of the cover-slip. 

 Any loss from the chamber by evaporation is prevented by 



