The new chemistry / by Josiah P. Cooke, Jr.

  • Josiah P. Cooke
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: The new chemistry / by Josiah P. Cooke, Jr. Source: Wellcome Collection.

    71/376 page 65
    removed from one auotlier to be free from all recipro- cal attraction, and subject only to the repulsive action of heat; and, from the facts, then already well estab- lished, that the same variations of temperature and press- ui-e produce in all gases nearly the same changes of vol- ume, he deduced the conclusion that equal volumes of all gases, compound as well as simple, contain, under like conditions, the same number of these molecules. This conception, simple and exact as it now appears, was at the time a mere hypothesis, and was not ad- vanced even with the semblance of proof. The discov- ery of Gay-Lussac, that gases combine in very simple proportions by volume, was made shortly after, and, had its important bearings been recognized at once, it would have been seen to be a most remarkable confir- mation of Avogadro's doctrine. But the new ideas passed almost unnoticed, and were reproduced by Am- pere in 1814, who based his theory on the experiments of Gay-Lussac, and defended it with far weightier evi- dence than his predecessor. Still, even after it was thus reafiirmed, the theory seems to have received but little attention either from the physicists or the chem- ists of the period. The reason appears to have been that the integrant moleoides of Avogadro and the par- ticles of Ampere were confused with the atoms of Dal- ton, and, in the sense which the chemists of the old school attached to the word atom, the proposition ap- peared to be true for only a very limited number even of the comparatively few aeriform substances which were then known. Moreover, the atomic theory itself was rejected by almost all the German chemists ; and, in physics, the theory of a matei'ial caloric then pre- vailing was not enforced by the new doctrine. In a word, this beautiful conception of Avogadro and Am- k2 ■ ,
    digitised image 1
    digitised image 2
    digitised image 3