Page 274 - Third Book of Reading Lessons

RE DING LESSONS.
273
Cu'BIC, a., having the rm of a cube-which is a square solid, having length, breadth, and depth; hence a "cubic ot" is 12 times 12 times 12 times, or 1728 inches. F. cubique, om (L.) cubus, G. kubos, a cube.
Fw'w, n., a term applied to that whose parts are easily separable·
anything that ows. F. uide, om 1 ere, L., to ow. CoTIGu'ous, a., bordering or adjoining; touching one another. L.
contiguus, om contingo,-con, and tango, I touch.
MER'CURY, n., quicksilver, which is one of the semi-metals, not bein malleable in our temperature: the metals are gold, silver, coppe
tin, iron, and lead.
MET1AL, n., a hard, compact body, sible and malleable (malleus, L.­ a mallet or hammer), i.e., capable, when beaten, of extension, with­ out the particles being separated. F. aud S. metal ; G. metallon, -meta, with, and allon, another; r where one vein is und, an­ other is presumed to be near.
REPUL1SION, n., the act or power of driving o om itself. L. repitl­ sus, a drawing back, a striking again, om repulso,-re, and pulso, I strike.
For "Process," see p. 150; "Granite," p. 223; "Sur ce," p. 258; "Sublime," p. 161; "Genius," p. 17; ''Solar," p. 122;--and r deriv. of "Globules," ( ttle globes), see "Globular," p. 155; and of "Constituent," see "Constitutes," p. 213.
To exemplify the process by which a general truth or law of nature is discovered, we shall take the physical law of gravity or attrac on. It was ob­ served that bodies in general, if raised om the earth, and left unsupported, ll towards it; while ame, smoke, vapours, &c., if left ee, ascended away om the earth. It was held, there re, to be a very general law, that things had weglit; but that
there were exceptions in such matters as were in their nature light or ascending. It was discovered that our globe of earth is surrounded by an ocean of air, having nearly y miles of altitude or depth, and of which a cubic ot, taken near the sur ce of the earth, weighs about an ounce. It was then per­ ceived that ame, smoke, vapour, &c., rise in the air only as oil rises in water, viz., becaus_ e not so heavy as the uid by which they are surrounded:
it llowed, there re, that nothing was knmvn on earth naturally liglit, in the ancient sense of the
'