That, for the moment at least, exhausted the interest in the Heavens, and man began to study the earth. The invention of a workable microscope, (a strange and clumsy little thing,) by Anthony van Leeuwenhoek during the last half of the 17th century, gave man a chance to study the "microscopic" creatures who are responsible for so many of his ailments. It laid the foundations of the science of "bacteriology" which in the last forty years has delivered the world from a great number of diseases by discovering the tiny organisms which cause the complaint. It also allowed the geologists to make a more careful study of different rocks and of the fossils (the petrified prehistoric plants) which they found deep below the surface of the earth. These investigations convinced them that the earth must be a great deal older than was stated in the book of Genesis and in the year 1830, Sir Charles Lyell published his "Principles of Geology" which denied the story of creation as related in the Bible and gave a far more wonderful description of slow growth and gradual development.
At the same time, the Marquis de Laplace was working on a new theory of creation, which made the earth a little blotch in the nebulous sea out of which the planetary system had been formed and Bunsen and Kirchhoff, by the use of the spectroscope, were investigating the chemical composition of the stars and of our good neighbour, the sun, whose curious spots had first been noticed by Galileo.
Meanwhile after a most bitter and relentless warfare with the clerical authorities of Catholic and Protestant lands, the anatomists and physiologists had at last obtained permission to dissect bodies and to substitute a positive knowledge of our organs and their habits for the guesswork of the mediaeval quack.
Within a single generation (between 1810 and 1840) more progress was made in every branch of science than in all the hundreds of thousands of years that had passed since man first looked at the stars and wondered why they were there. It must have been a very sad age for the people who had been educated under the old system. And we can understand their feeling of hatred for such men as Lamarck and Darwin, who did not exactly tell them that they were "descended from monkeys," (an accusation which our grandfathers seemed to regard as a personal insult,) but who suggested that the proud human race had evolved from a long series of ancestors who could trace the family-tree back to the little jelly-fishes who were the first inhabitants of our planet.
The dignified world of the well-to-do middle class, which dominated the nineteenth century, was willing to make use of the gas or the electric light, of all the many practical applications of the great scientific discoveries, but the mere investigator, the man of the "scientific theory" without whom no progress would be possible, continued to be distrusted until very recently. Then, at last, his services were recognised. Today the rich people who in past ages donated their wealth for the building of a cathedral, construct vast laboratories where silent men do battle upon the hidden enemies of mankind and often sacrifice their lives that coming generations may enjoy greater happiness and health.
Indeed it has come to pass that many of the ills of this world, which our ancestors regarded as inevitable "acts of God," have been exposed as manifestations of our own ignorance and neglect. Every child nowadays knows that he can keep from getting typhoid fever by a little care in the choice of his drinking water. But it took years and years of hard work before the doctors could convince the people of this fact.
Few of us now fear the dentist chair. A study of the microbes that live in our mouth has made it possible to keep our teeth from decay. Must perchance a tooth be pulled, then we take a sniff of gas, and go our way rejoicing. When the newspapers of the year 1846 brought the story of the "painless operation" which had been performed in America with the help of ether, the good people of Europe shook their heads. To them it seemed against the will of God that man should escape the pain which was the share of all mortals, and it took a long time before the practice of taking ether and chloroform for operations became general.
But the battle of progress had been won. The breach in the old walls of prejudice was growing larger and larger, and as time went by, the ancient stones of ignorance came crumbling down. The eager crusaders of a new and happier social order rushed forward. Suddenly they found themselves facing a new obstacle. Out of the ruins of a long-gone past, another citadel of reaction had been erected, and millions of men had to give their lives before this last bulwark was destroyed.
