Elements of physics, or, Natural philosophy : general and medical, written for universal use, in plain or non-technical language, and containing new disquisitions and practical suggestions / by Neil Arnott.

  • Arnott, Neil, 1788-1874.
Date:
1833
Catalogue details

Licence: Public Domain Mark

Credit: Elements of physics, or, Natural philosophy : general and medical, written for universal use, in plain or non-technical language, and containing new disquisitions and practical suggestions / by Neil Arnott. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    75/746 (page 37)
    A piece of wood sunk to a great depth in the ocean, and exposed to the pressure there, has its pores soon filled with water, and becomes nearly as heavy as stone. Thus it was with the boat of a whale-fishing ship, which had been dragged far under water by a whale, and which, on being afterwards drawn up, was supposed by the crew to be bringing a piece of rock with it. A piece of cork in a strong close glass vessel nearly full of water, may be seen floating at the top; but if more water be then forcibly pumped into the vessel, the cork will be squeezed and re- duced in size, until at last it becomes heavier than water and sinks. On water being afterwards allowed to escape, the cork will resume its bulk and will rise. A cork sunk 200 feet under water, will never rise again of itself. A bottle of fresh water, corked and let down thirty or forty feet into the sea, often comes up again with the water saltish, although the cork be still in its place: the explanation being, that the cork, when far down, is so squeezed as to allow the water to pass in or out by its sides, but on rising resumes its former size. Density,** or the quantity of atoms which exist in a given space, is very different in different substances. A cubic inch of lead is forty times heavier than the same bulk of cork. Mercury is nearly four- teen times heavier than an equal bulk of water. The density must depend on, first, the size or weight of the individual atoms; secondly, the