Still more numerous are the applications of Chemistry.  The bleacher, the dyer, the calico-printer, are severally occupied in processes that are well or ill done according as they do or do not conform to chemical laws.  Smelting of copper, tin, zinc, lead, silver, iron, must be guided by chemistry.  Sugar-refining, gas-making, soap-boiling, gunpowder-manufacture, are operations all partly chemical; as are likewise those which produce glass and porcelain.  Whether the distiller’s wort stops at the alcoholic fermentation or passes into the acetous, is a chemical question on which hangs his profit or loss; and the brewer, if his business is extensive, finds it pay to keep a chemist on his premises.  Indeed, there is now scarcely any manufacture over some part of which chemistry does not preside.  Nay, in these times even agriculture, to be profitably carried on, must have like guidance.  The analysis of manures and soils; the disclosure of their respective adaptations; the use of gypsum or other substance for fixing ammonia; the utilisation of coprolites; the production of artificial manures—­all these are boons of chemistry which it behoves the farmer to acquaint himself with.  Be it in the lucifer match, or in disinfected sewage, or in photographs—­in bread made without fermentation, or perfumes extracted from refuse, we may perceive that chemistry affects all our industries; and that, therefore, knowledge of it concerns every one who is directly or indirectly connected with our industries.

Of the Concrete sciences, we come first to Astronomy.  Out of this has grown that art of navigation which has made possible the enormous foreign commerce that supports a large part of our population, while supplying us with many necessaries and most of our luxuries.

Geology, again, is a science knowledge of which greatly aids industrial success.  Now that iron ores are so large a source of wealth; now that the duration of our coal-supply has become a question of great interest; now that we have a College of Mines and a Geological Survey; it is scarcely needful to enlarge on the truth that the study of the Earth’s crust is important to our material welfare.

And then the science of life—­Biology:  does not this, too, bear fundamentally on these processes of indirect self-preservation?  With what we ordinarily call manufactures, it has, indeed, little connection; but with the all-essential manufacture—­that of food—­it is inseparably connected.  As agriculture must conform its methods to the phenomena of vegetal and animal life, it follows that the science of these phenomena is the rational basis of agriculture.  Various biological truths have indeed been empirically established and acted upon by farmers, while yet there has been no conception of them as science; such as that particular manures are suited to particular plants; that crops of certain kinds unfit the soil for other crops; that horses cannot do good work on poor food;