Copy 1, Volume 3

A system of chemistry / [Thomas Thomson].

  • Thomas Thomson
Date:
1820-
Catalogue details

Licence: Public Domain Mark

Credit: A system of chemistry / [Thomas Thomson]. Source: Wellcome Collection.

    10/634 page 2
    ” Book HI. Chap. f. Attraction, Universal. AFFINITY. other; but when the mixture is thrown into water the acid unites with the alkali and expels the carbonic acid. Newton was the first person that gave a satisfactory expla- nation of the nature of affinity. Since his time the subject has occasionally attracted the attention of chemists. But the phi- losophers to whom we lie under the greatest obligations for the light which they have thrown on this difficult department of Chemistry are Bergman, onion ets Richter, Dalton, Davy, and Berzelius. As no complete theory of affinity can be exhibited at pre- sent, it will be requisite in this book to detail the general doc- trines of Chemistry as far as they have been hitherto ascer- tained. That we may omit no part of the subject I shall divide the book into five chapters. In the jirst I shall consider the nature of affinity in general; in the second I shall treat of gases; in the third of Liquids; in the fourth of Solids; and in the fifth of Decomposition. CHAP. I. OF AFFINITY IN GENERAL. 1. Axx the great bodies which constitute the solar system are urged towards each other by a force which preserves them in their orbits and regulates their motions. ‘This force has re- ceived the name of attraction. Its nature is unknown: whe- ther it be inherent in these bodies themselves, or the conse- quence of some foreign agent, are questions altogether beyond the reach of philosophy, because we have no method of de- ciding the point. One would be more inclined to the first supposition than to the other, as we can conceive no foreign agent sufficient to explain the planetary motions unless an in- telligent one; and, for any thing which we know to the con- trary, it was as easy for the Creator to have bestowed on the planets the power of acting on each other at a distance, as the power of being acted on, and receiving motion from other substances. 2. Sir Isaac Newton demonstrated, that this planetary at- traction is the same with gravitation, or that force by which a heavy body is urged towards the earth; that it is possessed, not only by the planets as wholes, but by all their component
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