System Dynamics

In terms of the quantum theory, a system is defined as a collection of bands corresponding to a common transition between two major electron levels. Sets of bands in a system can be selected such that the frequency intervals between successive bands in the set change in an arithmetic progression. These sets can be chosen in two different ways, the frequency intervals increasing in opposite directions in the two sets. Deslandres, who did the pioneer work in this field, called one series of such sets " first progressions," and the other series " second progressions." An entire system of bands, often eighty or more in number, can thus be represented as a function of two parameters p and n. The parameter n varies in a first progression, p remaining constant. The parameter p varies in a second progression, n remaining constant.

In the past the man has been first; in the future the system must be first. This in no sense, however, implies that great men are not needed. On the contrary, the first object of any good system must be that of developing first-class men

When a system is brought before the public, professing to be new, and claiming to be considered as peculiarly useful, it is incumbent on those who introduce it, to show in what respects it is original, and why it is an improvement.