IO 
PHARMACEUTICAL BOTANY 
4. Place the slide upright in a well of safranin for from four to 
twenty-four hours. 
5. Take the slide out of the safranin well and extract excess of 
stain with 50 per cent, alcohol. 
6. Place the slide in a well of gentian violet or methyl-green for a 
second or more. The time varies for different objects and can only 
be determined by trial. 
7. Rinse slide with 70 per cent, alcohol from pipette. 
8. Pour absolute alcohol over sections, follow with a few drops of 
clove oil, replace clove oil with cedar oil. 
9. Mount in balsam. 
MAKING OF SECTIONS 
Free-hand. Sectioning. — Free-hand sections are usually satisfactory 
for the general examination of roots, stems, leaves, barks and many 
fruits and seeds. Material which is fresh may be sectioned at once, 
but dry material should be well soaked in warm water before using. 
Very hard material like heartwoods, the shells of nuts and seeds, 
may be softened in solution of caustic potash or ammonia water 
and then washed free of alkali before sectioning. 
The object to be sectioned is held between the thumb and finger 
of the left hand, or, if small and of soft texture, it must be placed 
between two flat pieces of elder pith. The upper surface of the 
razor is wetted with water or 50 per cent, alcohol. The razor, which 
should be real sharp, is held in the right hand and is drawn across the 
object with the edge toward the student and the blade sliding on 
the forefinger of the left hand. The sections should be cut as thin 
as possible. As soon as a number of sections have been cut, they 
can be transferred to a vessel of water with a camel’s hair brush. 
Sectioning in Paraffine or Celloidin. — When it is necessary to study 
the microscopic structure of very delicate plant parts, the material 
should be imbedded in paraffine or celloidin, subsequently hardened, 
and sectioned by means of a sliding or rotary microtome. In your 
course this work will be carried on by the laboratory staff. 
KINDS OF SECTIONS 
1. A transverse or cross-section is one made horizontally through 
the object, hence its plane lies at right angles to the long axis. 
