With reference to all such further refinements of theory, it is to be borne in mind that the perfect fluid of hydrodynamic analysis is not a merely passive inert plenum; it is also a continuum with the property that no finite internal slip or discontinuity of motion can ever arise in it through any kind of disturbance; and this property must be postulated, as it cannot be explained.
We must be content to treat the aether as a plenum, which places it in a class by itself; and we can thus recognize that it may behave very differently from matter, though in some manner consistent with itself - a remark which is fundamental in the modern theory.
Questions of more than usual importance were, however, to be settled in the general assembly (Plenum) where a two-thirds majority was necessary to carry a resolution.
The representatives of the states favorable to this proposal, ic, Austria, Luxemburg, Denmark and the four kingdoms, came together in Frankfort on the 4th of September 1850, constituted themselves a Plenum of the old diet and refused to admit the other states except under the terms of the act of 1815.
Colour itself is not objective; it is found not in the ultimate plenum and vacuum, but only in derived objects according to their physical qualities and relations.