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 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.
At 25° to 30° C. it is soft and flexible, but it hardens when strongly cooled, and can then only be cut with difficulty.
In the older districts there is a countless variety of narrow gloomy streets, many of them steep. The houses are mostly five or six storeys high, are covered with stucco made of a kind of pozzolana which hardens by exposure, and have large balconies and flat roofs.
SCALE INSECT, a name given to insects belonging to the family Coccidae of the homopterous division of the Hemiptera and deriving their name from the formation by the females of a waxy secretion which often hardens into a protective scale beneath which the insects live.