The process of discovery is very simple.  An unwearied and systematic application of known laws to nature, causes the unknown to reveal themselves.  Almost any mode of observation will be successful at last, for what is most wanted is method.  Only let something be determined and fixed around which observation may rally.  How many new relations a foot-rule alone will reveal, and to how many things still this has not been applied!  What wonderful discoveries have been, and may still be, made, with a plumb-line, a level, a surveyor’s compass, a thermometer, or a barometer!  Where there is an observatory and a telescope, we expect that any eyes will see new worlds at once.  I should say that the most prominent scientific men of our country, and perhaps of this age, are either serving the arts and not pure science, or are performing faithful but quite subordinate labors in particular departments.  They make no steady and systematic approaches to the central fact.  A discovery is made, and at once the attention of all observers is distracted to that, and it draws many analogous discoveries in its train; as if their work were not already laid out for them, but they had been lying on their oars.  There is wanting constant and accurate observation with enough of theory to direct and discipline it.

But, above all, there is wanting genius.  Our books of science, as they improve in accuracy, are in danger of losing the freshness and vigor and readiness to appreciate the real laws of Nature, which is a marked merit in the ofttimes false theories of the ancients.  I am attracted by the slight pride and satisfaction, the emphatic and even exaggerated style in which some of the older naturalists speak of the operations of Nature, though they are better qualified to appreciate than to discriminate the facts.  Their assertions are not without value when disproved.  If they are not facts, they are suggestions for Nature herself to act upon.  “The Greeks,” says Gesner, “had a common proverb (Lagos katheudon) a sleeping hare, for a dissembler or counterfeit; because the hare sees when she sleeps; for this is an admirable and rare work of Nature, that all the residue of her bodily parts take their rest, but the eye standeth continually sentinel.”

Observation is so wide awake, and facts are being so rapidly added to the sum of human experience, that it appears as if the theorizer would always be in arrears, and were doomed forever to arrive at imperfect conclusions; but the power to perceive a law is equally rare in all ages of the world, and depends but little on the number of facts observed.  The senses of the savage will furnish him with facts enough to set him up as a philosopher.  The ancients can still speak to us with authority, even on the themes of geology and chemistry, though these studies are thought to have had their birth in modern times.  Much is said about the progress of science in these centuries.