Impenetrability
one of the essential properties of matter, implies that no two bodies can at the same time occupy the same space. If a nail be driven into a piece of wood, it does not, propthe fibers are driven aside before the erly speaking, penetrate the wood, for nail can enter. If a vessel be filled with fluid, and a solid body be then placed in it, as much water will run over as is equal in bulk to the solid body, in this way making room for it.
IMPERATOR (im-per-a'tor), a title originally bestowed upon a victorious leader on the field of battle by his soldiers; toward the end of the commonwealth it was conferred by the Senate. Augustus and his successors constantly assumed this title, and it became the peculiar appellation of supreme power.
Still later it became equivalent to the modern emperor. In zoölogy, a genus of gasteropodous mollusks, family Turbinidæ. About 20 species are known from South Africa, India, Australia, and New Zealand.
IMPERATORIN C12H12O3, peucedanin, a neutral substance (im-per-ä-tor'in), destitute of taste and smell, obtained from the root of the masterwort by digesting it in boiling alcohol and purifying, by means of ether, from a brown resinous body with which it is contaminated.