Coleridge says in "Table Talk,"--"I have seen what I am certain I would not have believed on your telling; and in all reason, therefore, I can neither expect nor wish that you should believe on mine." It is of all tasks the most difficult to procure any favourable reception for doctrines which are objectionable only because they are deemed to be incompatible with preconceived notions. It does not answer to disturb the calmness of views now held by our most eminent physicists, who seem to expect that nature will always accommodate her operations to their preconceived notions of possibility, and adapt her phenomena to their arbitrary systems of philosophy. We are all familiar with the anecdote of the wise Indian potentate who imagined that his informant was imposing upon his credulity when giving him an accurate description of the steam-engine. Now what would be thought of that philosopher who, in attempting to communicate an adequate idea of the operation of the steam-engine, should content himself with a mere description of its mechanism--of its wheels and levers, and cylinders and pistons--keeping entirely out of view the moving power--the steam; and ridiculing all investigation into the nature, application, and phenomena of this power. Yet this is exactly what microscopic observers of the animal economy call "absurd and useless inquiry." The true springs of our organization are not these muscles, these arteries, these nerves, which are described and experimented upon with so much care and exactness. They are hidden springs, the action of which are as miracles to those who have vainly tried to account for the motion of the muscles at the command of the will; for the power of vision, which places the human eye in intimate and immediate connection with the soul--dependent as they are upon unknown laws, assigned them by the great, omniscient and omnipotent Being by whom they were originally created, and Who is the one source of all power.
Although in our present ordinary state of existence we are permitted to see only "as through a glass darkly," ignorant of many of the powers and processes of nature, as well as of the causes to which they are to be ascribed, we are not, therefore, entitled to set limits to her operations, and to say to her, "Hitherto shalt thou go, and no further! "We must not presume, says Glanvill, to assign bounds to the exercise of the power of the Almighty, nor are these operations and that power to be controlled by the arbitrary theories and capricious fancies of man. We are surrounded by the incredible--the seemingly miraculous. Who would not ask for demonstration when told that a gnat's wing, in its ordinary flight, beats many hundred times in a second? But what is this, when compared to the astonishing truths which modern optical inquiries reveal--such as teach us that the sensation of violet light affects our eyes 707 millions of millions of times per second in order to effect that sensation?