Moreover, he has often observed that objects which appear continuous when seen from a distance are evidently far from continuous when seen close at hand.

As we walk toward a tree we can see the indefinite mass of color break up into discontinuous patches; a fabric, which presents the appearance of an unbroken surface when viewed in certain ways may be seen to be riddled with holes when held between the eye and the light.

There is no man who has not some acquaintance with the distinction between appearance and reality, and who does not make use of the distinction in common life.
Nor can it seem a surprising fact that different combinations of atoms should exhibit different properties.

Have we not always known that things in combination are apt to have different properties from the same things taken separately?
He who does not know so much as this is not fit even to be a cook.
No, the imperceptible world of atoms and molecules is not by any means totally different from the world of things in which the plain man lives.

These little objects and groups of objects are discussed very much as we discuss the larger objects and groups of objects to which we are accustomed.