ABSTRACT
Human existence hangs between two great worlds, the infinitely great and the infinitely little, and into both the chemist can penetrate. Ordinary microscopes may give a magnification amounting, under favourable circumstances, to as much as 3000 diameters, and so render visible objects which have a size represented by about one ten-thousandth of a millimetre across. Something is at last beginning to be understood regarding the constitution of that peculiar state of matter to which the name “colloid” has been given. At the end of the nineteenth entury every chemist and physicist believed in the permanence of the atom as the fundamental unit of mass. Since that time it has been shown not only that certain special types of atoms break up spontaneously, but that all atoms under cathodic discharge yield smaller bodies, electrons, which have only about 11800 th part of the mass of an atom of hydrogen.
