study, let him or her aid the writer in a practical way and send a contribution to help circulate these ideas, not only in English and other languages but in other countries as well as the United States.

The address of the author is: The Congressional, 100 East Capitol Street, Washington, D. C.

EQUATION OF THE DEMOGRAPHIC LAW OF INTERDEPENDENCE OF NATIONS.

As already noted, our demographic law of the interdependence of nations is, that increase in the means of communication between States causes increase of their interdependence but decrease in their sovereignty. Just as a physical body consists of molecules of various kinds, so the State may be regarded as a psychological entity with citizens of various characteristics, and just as the density of a body is equal to its mass divided by its volume, so the density of citizenship is equal to the population divided by the land area.

If, therefore, we consider the States' adult population, as its mass (m) and the resultant aggregate increase of its means of communication as its velocity (v), and (t) as the time, then the psychological force (F) or interdependence of the State can be expressed by the familiar equation in physics F=mv/t; that is to say, the interdependence of a State is equal to its adult population (mass) multiplied by the resultant aggregate increase of its means of communication (velocity) and the product divided by the time (t).

The poundal unit of physical force is such a force as will move 1 pound (mass unit) at a velocity of 1 foot per second in one second of time.

Now, assuming the unit of citizenship of a State to be one citizen and the unit of the resultant aggregate increase of means of communication per annum in one year of time to be K, then

The statal unit of psychological force is such a force as will give one citizen (mass unit) one K unit (for convenience the K unit of annual aggregate increase of means of communication can be expressed in per cents. Taking some of the principal means of communication, and working out their annual average per cents of increase, we have for the United States during the census periods (1900-1910); annual average increase of passengers on railroads, 7 per cent; on street and electric railways, 3 per cent (1907-1912); of telegraph messages sent, 6 per cent; of telephone stations, 10 per cent. Combining these, the per cent of annual average aggregate increase will be 6.5 per cent, as value of K, assuming the percentages are equally weighted) of resultant aggregate increase of means of communication per annum in one year of time.

As yet there is no exact way to measure the sovereignty and means of communication of the State, but the psychological side of this physical equation may suggest a working hypothesis for our demographic law of the interdependence of States which may some time be useful in the realm of international psychology.

To measure the aggregate influence upon citizens of the many means of communication in a State (also, for illustration merely, let us take one of the principal means of communication, as steam railroads, and we find that the annual average increase in passenger-train-car miles for one citizen of the United States, from 1908 to 1914, to be 4.45, which is the value of K for steam railroads alone for period mentioned. In a later article the author will consider in detail the practical application of the equation) as steam, street and electric railways, telegraph and telephones, will require exact detailed knowledge of the mental, moral, and physical power of the individual citizen, the unit of the social organism. Such measurements might be made when psychology and sociology become sciences in the rigid sense. The underlying hypothesis in this equation is that both the psychological and physical mechanism of the world are under one fundamental law.[7]

Laws of Revolution.[8]

Scientific history teaches that without war many revolutions could never have taken place. One of the greatest problems of future government is to reconcile democratic equality with hereditary inequality among the people. Governments differ much more in form than in substance, and make progress when the resultant activities of the citizens direct and control them.

With this in mind, a few principles of revolutions may be instructive in connection with the present European situation.

1. The causes of revolutions are summed up in the word "discontent," which must be general and accompanied with hope in order to produce results.

2. Modern revolutions appear to be more abrupt than ancient. Contrary to expectation, conservative people may have the most violent revolutions, because of not being able to adapt themselves to changes of environment.

3. Revolution owes its power to the unchaining of the people, and does not take place without the aid of an important fraction of the army, which usually becomes disaffected by power of suggestion.

4. The triumphant party will organize according to whether the revolution is effected by soldiers, radicals, or conservatives.

5. The violence is liable to be great if a belief as well as material interests are being defended.

6. For ideas which cause violent contradictions are matters of faith, rather than of knowledge.

7. If the triumphant party go to extremes, bordering upon absurdities, they are liable to be turned down by the people.

8. Most revolutions aim to put a new person in power, who usually tries to establish an equilibrium between the struggling factions, and not be too much dominated by any one class.

9. The rapidity of modern revolutions is explained by quick methods of publicity, and the slight resistance and ease with which some governments have been overturned is surprising, indicating blind confidence and inability to foresee.

10. Governments sometimes have fallen so easily that they are said to have committed suicide.

11. Revolutionary organizations are impulsive, though often timid, and are influenced by a few leaders, who may cause them to act contrary to the wishes of the majority. Thus royal assemblies have destroyed empires and humanitarian legislatures have permitted massacres.

12. When all social restraints are abandoned, and instinctive impulses are allowed full sway, there is danger of return to barbarianism. For the ancestral ego (inherent in everyone) is let loose.

13. A country will prosper in proportion that the really superior persons rule, and this superiority is both moral and mental.

14. If certain social tendencies appear to lower the power of mind, they, nevertheless, may lessen injustice to the weaker classes; and if it be a choice between mentality and morality, morality should be preferred.

15. A financial aristocracy does not promote much jealousy in those who hope to form a part of it in the future.

16. Science has caused many things once held to be historical to be now considered doubtful. Thus it is asked—

17. Would not the results of the French Revolution, which cost so much bloodshed, have been obtained without violence later, through gradual evolution? And were the results of the French Revolution worth the cost of the terrible barbarism and suffering that took place?

18. To understand the people in a revolution we must know their history.

19. The accumulated thought, feeling, and tradition of a nation constitute its strength, which is its national spirit. This must not be too rigid, nor too malleable. For, in the first place, revolution means anarchy, and, in the second place, it results in