Invention breeds invention. No sooner is the electric telegraph devised, than gutta-percha, the very material it requires, is found. The aeronaut is provided with gun-cotton, the very fuel he wants for his balloon. When commerce is vastly enlarged, California and Australia expose the gold it needs. When Europe is over-populated, America and Australia crave to be peopled; and so, throughout, every chance is timed, as if Nature, who made the lock, knew where to find the key. Another result of our arts is the new intercourse which is surprising us with new solutions of the embarrassing political problems. The intercourse is not new, but the scale is new. Our selfishness would have held slaves, or would have excluded from a quarter of the planet all that are not born on the soil of that quarter. Our politics are disgusting; but what can they help or hinder when from time to time the primal instincts are impressed on masses of mankind, when the nations are in exodus and flux? Nature loves to cross her stocks,--and German, Chinese, Turk, Russ, and Kanaka were putting out to sea, and intermarrying race with race; and commerce took the hint, and ships were built capacious enough to carry the people of a county. This thousand-handed art has introduced a new element into the state. The science of power is forced to remember the power of science. Civilization mounts and climbs. Malthus, when he stated that the mouths went on multiplying geometrically, and the food only arithmetically, forgot to say that the human mind was also a factor in political economy, and that the augmenting wants of society would be met by an augmenting power of invention. Yes, we have a pretty artillery of tools now in our social arrangements: we ride four times as fast as our fathers did; travel, grind, weave, forge, plant, till, and excavate better. We have new shoes, gloves, glasses, and gimlets; we have the calculus; we have the newspaper, which does its best to make every square acre of land and sea give an account of itself at your breakfast-table; we have money, and paper money; we have language,--the finest tool of all, and nearest to the mind. Much will have more. Man flatters himself that his command over nature must increase. Things begin to obey him. We are to have the balloon yet, and the next war will be fought in the air. We may yet find a rose-water that will wash the negro white. He sees the skull of the English race changing from its Saxon type under the exigencies of American life.