In a usual way the greatest pecuniary benefits, arising from science, sooner or later go to enrich the possessors of land. The demand created for coal, iron, lime, building-stone, and all the metals, by the industrial applications of science, has greatly increased the value of land under which those substances lie. The value of cultivated land has been everywhere increased by the discoveries of agricultural chemistry. Land has also been required for railways in nearly all parts of the kingdom, and has thereby been considerably raised in value. Discoveries produce inventions, inventions give rise to processes and manufactures, the employment of workmen and others, and the erection of workshops and dwellings, and these have rapidly increased the value of building ground. In Lancashire the value of such ground has been greatly increased by the inventions of the steam-engine and machinery, the discovery of chlorine, and their application to cotton manufacture. In all the great manufacturing districts, and in all the chief centres of industry, a similar result has occurred. Wherever a railway has been constructed, the value of land has also increased in {32} consequence of the increased facilities of communication. All these great additions to the value of land are largely due to the unpaid labours of scientific discoverers, and it may be said that this nation has largely gained its wealth, and is still living in a great degree on the products of those labours. Those great additions to the value of land are also permanent, are continually increasing, and are largely independent of any exertions on the part of the owners. That many other influences, besides that of science, have contributed to the development of our manufacturing and commercial prosperity is also true, but it would be foreign to the subject of the present chapter to point them out. It is a fallacious argument to say that scientific discovery and increased value of land are only remotely connected together, a cause as certainly produces its effect, however many connections lie between them, provided the connections are certain--the number of links in a chain makes no difference in the transmission of motion from one end of it to the other. Great causes are frequently distant and wide-spread in their effects. Persons in general can easily understand that an acorn planted in the ground will in the course of time become an oak, because it is a palpable and visible effect; but they cannot so readily perceive that the benefits resulting from a knowledge of science ramify through all our manufacturing, artistic, and commercial occupations, our social and moral {33} relations, and our every-day life, not because the dependence of our welfare upon science is less real, but partly because the connection between the two is less understood.