Volume 1

A system of chemistry ... / [John Murray].

  • John Murray
Date:
1806-1807
Catalogue details

Licence: Public Domain Mark

Credit: A system of chemistry ... / [John Murray]. Source: Wellcome Collection.

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    The actions of chemistry are more obscure and in- stantaneous ; taking place only at the point of contaét, they admit of no precise calculation as to their inten- sity ; and are discoverable almost solely from changes in the constitution of the bodies between which they have been exerted. | : In the last place, chemical ation, by uniting the particles of matter, changes their existing arrange- ment; subverts the properties of bodies, and pro- duces others with qualities more or less different. It is a striking character of chemical ation, thus to give origin to substances having new properties; and it may justly be regarded as the great source of the various qualities with which bodies are endowed. From any other species of physical action no change of this kind results. The effect is merely to excite or communicate motion, or to modify it in masses of matter, whence no alteration in their intimate consti- tution can be produced. The different objects of these two departments of physical science might easily be illustrated by the slightest survey of the different points of view under which the same substances are studied by the Mecha- nical and Chemical Philosopher. The one, for example, in subjetting Light to his examination, considers it merely as a substance of great tenuity, moving with velocity in right lines, and capable of having its mo- tion stopt, or its direction changed by the action of other bodies upon it, giving rise, by these actions, to the phenomena of optics. The other, without at- tending maich to the phenomena which the motion of A 2
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