120 
METHODS IN PLANT HISTOLOGY 
which will keep as well as Mayer’s fixative; but make the bichromate 
solution immediately before using. Do not make the solution 
stronger than 1 per cent; usually 0.2 per cent is strong enough. 
Dr. Land does not measure, but simply adds enough bichromate 
crystals to make the water pale yellow. 
Smear a few drops of the 1 per cent solution of gum arabic on the 
slide; flood with the bichromate solution; warm to straighten the 
ribbons; drain off the excess water and let the preparation dry in 
the light. The exposure to light renders the gum insoluble in water. 
LePage’s glue or Mayer’s albumen fixative may be used instead of 
gum arabic. 
The foregoing directions are taken from Dr. Land’s notes. 
With the ordinary Mayer’s albumen fixative the bichromate of 
potash, without the gum arabic, may be used in floating out ribbons, 
and makes a stronger fixative than the Mayer’s formula. 
Szombathy’s Fixative.— 
Gelatin... 1 g. 
Distilled water. 100 c.c. 
Salicylate of soda (a 2 per cent solution). 1 c.c. 
Pure glycerin. 15c.c. 
Dissolve the gelatin in water at 30° C., add the salicylate of soda, 
shake well, cool, and filter through cheese-cloth; then add the 15 c.c. 
of glycerin. The solution should be perfectly clear. 
A couple of drops of the fixative,.with a couple of drops of 2 per cent 
formalin, is rubbed on the slide. The sections are then added, and 
straightened out. The formalin makes the gelatin insoluble. The 
fixative is much like Land’s and is used for difficult material which is 
not held by Mayer’s fixative. 
REMOVAL OF THE PARAFFIN 
To remove the paraffin, place the slide in a Stender dish of xylol. 
About 5 minutes will be sufficient for sections 10 u thick. The time 
may be shortened a little by gently warming the slide. Never heat 
the slide enough to melt the paraffin. Never attempt to warm the paraf¬ 
fin over a lamp. Overheating is ruinous. 
Many prefer to remove the paraffin by pouring on xylol or 
turpentine. Hold the slide at an angle of 45°, and pour on a little 
xylol or turpentine. If the slide has been slightly warmed this 
should carry off the paraffin immediately. The reagent used in 
