The striking periodicity of the wars in Europe is also noticed by Dr. E. Zasse. Beginning with 1700 A.D., every ten years have been signalized by either a war or a revolution. The periods of the strengthening and weakening of the warlike excitement of the European nations represent a wave strikingly regular in its periodicity, flowing incessantly, as if propelled onward by some fixed inscrutable law. This same mysterious law seems also to connect these events with the astronomical wave or cycle, which governs the periodicity of solar spots. The periods when the European powers have shown the most destructive energy are marked by a cycle of fifty years' duration. It would be too long and tedious to enumerate them from the beginning of history. We may, therefore, limit our study to the cycle beginning with the year 1712, when all the European nations were fighting each other in the Northern, and the Turkish wars, and the war for the throne of Spain. About 1761, the "Seven Years' War"; in 1810, the wars of Napoleon I. Towards 1861, the wave has been a little deflected from its regular course; but, as if to compensate for it, or propelled, perhaps, with unusual force, the years directly preceding, as well as those which followed it, left in history the records of the most fierce and bloody wars--the Crimean War in the former, and the American Civil War in the latter period. The periodicity in the wars between Russia and Turkey appears peculiarly striking, and represents a very characteristic wave. At first the intervals between the cycles of thirty years' duration--1710, 1740, 1770 then these intervals diminish, and we have a cycle of twenty years--1790, 1810, 1829-30; then the intervals widen again--1853 and 1878. But if we take note of the whole duration of the in-flowing tide of the war-like cycle, then we shall have at the centre of it--from 1768 to 1812--three wars of seven years' duration each, and at both ends, wars of two years. Finally, the author comes to the conclusion that, in view of facts, it becomes thoroughly impossible to deny the presence of a regular periodicity in the excitement of both mental and physical forces in the nations of the world. He proves that in the history of all the peoples and empires of the Old World, the cycles marking the millenniums, the centennials as well as the minor ones of fifty and ten years' duration, are the most important, inasmuch as neither of them has ever yet failed to bring in its train some more or less marked event in the history of the nation swept over by these historical waves. The history of India is one which, of all histories, is the most vague and least satisfactory. Yet were its consecutive great events noted down, and its annals well searched, the law of cycles would be found to have asserted itself here as plainly as in every other country in respect of its wars, famines, political exigencies, and other matters.