A Survey of Experimental Philosophy Author:Oliver Goldsmith Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAP. IV. Qf Air confidered as a Fluid. SUCH are the moft obvious of that heterogenepus affemblage of bodies In our atmofphere; but that fine and perfectly... more » tranfparent fubftance the true natural air which fupports them, comes next to be taken into confideration; and its fluidity, or the eafy yielding of its parts, is one pf the moft obvious of its properties. The eafe with which it gives way to the fwifteft bodies need fcarce be mentioned; founds travel through it with great rapidity, odours and emanations of all kinds find no difficulty in moving forward and preffing afide its parts to make way for fhejr own. Thefe all Mempnftrate the air to be a moft yielding fubftance which gives way, if not prevented, to every impreffion ; and this is but another name for fluidity. Thi§fluid quality the air never lofes, though it be kept never fo long in the clofeft veflels, though it be expofed to the grcateft viciffitudes of heat or cold, or though it be preft together with the ut- moft violence of human force affifted by machinery. Still the air continues that yielding fluid it was at firft; in all thefe; cafes it was n?ver found that any of its parts became folid, and unbending to the touch, or that they were reduced into any other fubftance different from air. Why the parts of this fluid ftill retain their ufual form we cannot tell; to un- derftand this would require a knowledge of the figure of the fmall parts of air themfelves; to underfland this, it would be neceflary to know the dimenfions of thofe fmall parts, and alfo to know their mutual tendency to attract or repell each other. None of thefe however are known to us, and therefore the caufe of the airs fluidity muft ftill remain a fecret; it is fufficient that we know that it is a fluid, the appearance and not the caufe is al...« less