The viscid pulp soon hardens, affording a protection to the seed; in germination the sucker-root penetrates the bark, and a connexion is established with the vascular tissue of the first plant.
If, on the other hand, the alcohol be rubbed into the skin, or if its evaporation be prevented - as by a watch-glass - it absorbs water from the tissues and thus hardens them.
The soap is melted by heat, the glycerin is stirred in, and the mixture strained and poured into forms, in which it hardens but slowly into a transparent mass.
At ordinary temperatures the metal has the consistency of wax and can be readily cut; on cooling it hardens.
In those containing water in the rainy season only, the fish preserve life when the bed is dry by burrowing deeply in the ooze before it hardens.