But flour, water, and other materials of bread, according to our definition, are not elementary substances?
MRS. B.
No, my dear; I mentioned bread rather as a familiar comparison, to illustrate the idea, than as an example.
The elementary substances of which a body is composed are called the constituent parts of that body; in decomposing it, therefore, we separate its constituent parts. If, on the contrary, we divide a body by chopping it to pieces, or even by grinding or pounding it to the finest powder, each of these small particles will still consist of a portion of the several constituent parts of the whole body: these are called the integrant parts; do you understand the difference?
EMILY.
Yes, I think, perfectly. We decompose a body into its constituent parts; and divide it into its integrant parts.
MRS. B.
Exactly so. If therefore a body consists of only one kind of substance, though it may be divided into its integrant parts, it is not possible to decompose it. Such bodies are therefore called simple or elementary, as they are the elements of which all other bodies are composed. Compound bodies are such as consist of more than one of these elementary principles.
CAROLINE.
But do not fire, air, earth, and water, consist, each of them, but of one kind of substance?