If, however, by the term "infinite divisibility," as applied to matter, is merely meant its capacity for interminable subdivision, then the question resolves itself either into one of speculative fancy or of practical fact. If the former, then it must be admitted that, by an effort of the imagination, we can conceive of such a divisibility beyond any assignable limits. But if we regard the question as a practical one, it immediately becomes too absurd for serious attention, since it is evident that human power, limited in all things, must be so in producing artificial subdivisions of matter. However unlimited, therefore, the capacity of matter may be for divisibility, that of human beings, in relation to it, must be narrow indeed. When chemists, therefore, and other philosophers, speak of the divisibility of the present ultimate atoms of matter, they must, however unconsciously, regard them in relation to human ability, and thus far the question may become one of experiment. But the question as to whether matter can actually be subdivided indefinitely and without end, is one readily answered in the negative, by the known inability of mankind to continue an endless experiment of this kind. The whole question therefore, concerning the illimitable divisibility of matter, which has been discussed from the earliest period of science to the present day, is frivolous, fruitless, and irrational.
As matter now exists, not only its ultimate atoms, but even its constituent molecules, are as inconceivably minute, as its aggregations are vast. Taking an exemplification, from organic matter, we find that a single drop of a strong solution of indigo, in which at least 500,000 parts are rendered distinctly visible by the microscope, colors 1,000 cubic inches of water, and as this quantity of water is at least half a million of times greater than the drop of indigo solution, the particles of indigo must be smaller than 2,500,000,000,000, the twenty-five hundred millionth part of a cubic inch. If we dissolve a particle of silver, of 0.01 of a cubic _line_, in size, in nitric acid, it will render distinctly milky 500 cubic inches of a clear solution of common salt; and, consequently, the magnitude of each particle of silver thus divided and diffused, must be somewhat less than the billionth part of a cubic _line!_ So great a number as a billion being but imperfectly conceivable, it may render the idea of this minute division more distinct, by stating that to count a single billion of seconds, by a watch, every day and night without ceasing, would require 31,675 years. In gilding silver wire, it is found, by calculation, that a grain of gold is spread over 1,400 square inches; and as, when examined by a microscope, the gold upon the thousandth part of a linear inch is distinctly visible, it is demonstrated that gold may be divided into particles of at least the billionth, 400 millionth, of a square inch in size, and retain the color and all other characteristics of a California prize. If a grain of copper be dissolved in nitric acid, and then in water of ammonia, it will give a decidedly violet color to 392 cubic inches of water; and, therefore, if there was but one particle of copper in each portion of the water of the size of a grain of sand, of which one million make a cubic inch, it would show that the original grain of copper had become divided into 392 particles.