work until obtaining a greenish juice of the leaves.
The liquefied material was sifted through a 0.20 mm
sieve. A sample of 20 crystals extracted from croton
leaves was measured and the values varied from 0.004
to 0.018 mm. The 0.20 mm sieve was adequate to
separate the fibrous leaf material from the plant juice
and the CaOx crystals. The plant material retained
in the sieve was ground again in the blender. The
procedure must be repeated until the plant juice
becomes totally clear.