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netrable; -- used especially of substances which allow the passage of fluids; as, wood is permeable to oil; glass is permeable to light. I. Taylor.

Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable; as, India rubber is impermeable to water and to air. -- Im*per"me*a*ble*ness, n. -- Im*per"me*a*bly, adv.

So tight as to be impermeable to air; as, an air-tight cylinder.

the euphorbiaceous tree Siphonia elastica or Hevea caoutchouc), Asia, and Africa. Being impermeable to liquids and gases, and not readly affected by exposure to air, acids, and alkalies, it is used, especially when vulcanized, for many purposes in the arts and in manufactures. Also called India rubber (because it was f…

Dry and hard; impermeable; unyielding. [Obs.] Clay in dry seasons is costive, hardening with the sun and wind. Mortimer.

Freely permeable by radiant heat.

The quality of being impermeable.

Rays emanating from the outer surface of a plate composed of any material permeable by cathode rays, as aluminium, which forms a portion of a wall of a vacuum tube, or which is mounted within the tube and exposed to radiation from the cathode. Lenard rays are similar in all their known properties to cathode rays. So ca…

The quality or state of being permeable. Magnetic permeability (Physics), the specific capacity of a body for magnetic induction, or its conducting power for lines of magnetic force. Sir W. Thomson.

In a permeable manner.

Admitting passage; capable of being penetrated by another body or substance; permeable; as, a pervious soil. [Doors] . . . pervious to winds, and open every way. Pope.

ces in the skin or in the substance of the body; having spiracles or passages for fluids; permeable by liquids; as, a porous skin; porous wood. "The veins of porous earth." Milton.

The case, or impermeable apparel, in which a diver can work while under water.