orbit. This, however, would hardly seem to be a general property of the binding of the
th electron in atoms, but rather to arise from the special conditions for the binding of the last electron in an atom, where already there are two other electrons bound as loosely as the valency electron of aluminium. At the present state of the theory it seems best to assume that in the silicon atom the four last captured electrons will move in
orbits forming a configuration possessing symmetrical properties similar to the outer configuration of the four electrons in
orbits in carbon. Like what we assumed for the latter configuration we shall expect that the configuration of the
orbits occurring for the first time in silicon possesses such a completion, that the addition of a further electron in a