Or take again the discovery of anaesthetics. At the beginning of the century Sir Humphrey discovered laughing gas, as it was then called. He found that it produced complete insensibility to pain and yet did not injure health. A tooth was actually taken out under its influence, and of course without suffering. These facts were known to our chemists, they were explained to the students in our great hospitals, and yet for half a century the obvious application occurred to no one. Operations continued to be performed as before, patients suffered the same horrible tortures, and yet the beneficent element was in our hands, its divine properties were known, but it never occurred to any one to make use of it.
I may give one more illustration. Printing is generally said to have been discovered in the fifteenth century; and so it was for all practical purposes. But in fact printing was known long before. The Romans used stamps; on the monuments of Assyrian kings the name of the reigning monarch may be found duly printed. What then is the difference? One little, but all-important step. The real inventor of printing was the man into whose mind flashed the fruitful idea of having separate stamps for each letter, instead of for separate words. How slight seems the difference, and yet for 3000 years the thought occurred to no one. Who can tell what other discoveries, as simple and yet as far-reaching, lie at this very moment under our very eyes!
Archimedes said that if you would give him room to stand on, he would move the earth. One truth leads to another; each discovery renders possible another, and, what is more, a higher.
We are but beginning to realize the marvelous range and complexity of Nature. I have elsewhere called attention to this with special reference to the problematical organs of sense possessed by many animals. [2]
There is every reason to hope that future studies will throw much light on these interesting structures. We may, no doubt, expect much from the improvement in our microscopes, the use of new re-agents, and of mechanical appliances; but the ultimate atoms of which matter is composed are so infinitesimally minute, that it is difficult to foresee any manner in which we may hope for a final solution of these problems.