26 THE POPULAR SCIENCE MONTHLY. 



its more warlike and less scrupulous neighbors. Progress in civiliza- 

 tion must necessarily be very slow, and to be permanent must pervade 

 all classes and all the surrounding nations ; and it is because past civ- 

 ilizations have been too partial that there have been so many relapses 

 into comparative barbarism. All this is carefully worked out, and is 

 well worthy of attention. 



In the last section, on the probable future of the human race, we 

 have some remarkable speculations, very different from the somewhat 

 Utopian views held by most evolutionists, but founded, nevertheless, on 

 certain very practical considerations. In the next few hundred or a 

 thousand years the chief alterations will be the extinction of all the 

 less dominant races, and the partition of the world among the three 

 great persistent types, the whites, blacks, and Chinese, each of which 

 will have occupied those portions of the globe for which they are best 

 adapted. But, taking a more extended glance into the future of 50,000 

 or 100,000 years hence, and supposing that no cosmical changes occur 

 to destroy, wholly or partially, the human race, there are certain well- 

 ascertained facts on which to found a notion of what must by that time 

 have occurred. In the first place, all the coal and all the metals avail- 

 able will then have been exhausted, and, even if men succeed in find- 

 ing other sources of heat, and are able to extract the metals thinly 

 diffused through the soil, yet these products must become far dearer* 

 and less available for general use than now. Railroads and steam- 

 ships, and every thing that depends upon the possession of large quan- 

 tities of cheap metals, will then be impossible, and sedentary agricul- 

 tural populations in w r arm and fertile regions will be the best off. 

 Population will have lingered longest around the greatest masses of 

 coal and iron, but will finally become most densely aggregated within 

 the tropics. But another and more serious change is going on, which 

 will result in the gradual diminution and deterioration of the terres- 

 trial surface. Assuming the undoubted fact that all our existing land 

 is wearing away and being carried into the sea, but, by a strange over- 

 sight, leaving out altogether the counteracting internal forces, which 

 for countless ages past seem always to have raised ample tracts above 

 the sea as fast as subaerial denudation has lowered them, it is argued 

 that, even if all the land does not disappear and so man become finally 

 extinct, yet the land will become less varied, and will consist chiefly 

 of a few flat and parched-up plains, and volcanic or coralline islands. 

 Population will by this time necessarily have much diminished, but it 

 is thought that an intelligent and persevering race may even then 

 prosper. "They will enjoy the happiness which results from a peace- 

 able existence, for, without metals or combustibles, it will be difficult 

 to form fleets to rule the seas, or great armies to ravage the land ; " 

 and the conclusion is that " such ai-e the probabilities according to the 

 actual course of things." Now, although we cannot admit this to be 

 a probability on the grounds stated by M. de Candolle, it does seem a 



