Historic Inventions

by Rupert Sargent Holland

Davy was an eloquent, enthusiastic, forceful speaker. He prepared his lectures with the greatest care, and he delivered them with that attention to dramatic effect which is instinctive in all really great speakers. Coleridge said, “I attend Davy’s lectures to increase my stock of metaphors,” and there were many others who went to hear the young chemist for other reasons than a liking for science. He had his own theories of the arts of public address. “Great powers,” said he, “have never been exerted independent of strong feelings. The rapid arrangement of ideas from their various analogies to the equally rapid comparisons of these analogies, with facts uniformly occurring during the progress of discovery, have existed only in those minds where the agency of strong and various motives is perceived—of motives modifying each other, mingling with each other, and producing that fever of emotion which is the joy of existence and the consciousness of life.”

In addition to his lectures Davy worked hard in the well-stocked laboratory of the Institution, where he was supplied with a corps of capable assistants. His researches covered a very large part of the field of chemistry, and he was indefatigable in running down any new idea which his active brain chanced to hit upon. In his vacations from London he went to the farthest regions of the British Isles, spending considerable time in the north of Ireland and the Hebrides. Here he studied the geological structures, and collected all the information he could in regard to agriculture. Anything to do with natural science interested him. He sketched a great deal, and he was forever asking questions of all the countrymen he met. His questions made him famous in many a hamlet, where such inquisitiveness had never been known before.

Shortly after he had moved to London he had been asked to investigate astringent plants in connection with tanning. To this end he visited tan-yards and farmers, and in 1802 began to deliver a course of lectures on “The Connection of Chemistry with Vegetable Physiology.” These lectures proved remarkably popular, and for ten years he repeated them at the meetings of the Board of Agriculture. They were later published in book form, and so great was their interest that they were translated into almost every European language. The Edinburgh Review, that dean of British critics, said, “We feel grateful for his having thus suspended for a time the labors of original investigation, in order to apply the principles and discoveries of his favorite science to the illustration and improvement of an art which, above all others, ministers to the wants and comforts of man.”

When his agricultural researches were finished he went back to his studies with the voltaic pile or battery. He discovered that potash and soda can be decomposed, with the resultant metals of potassium and sodium. When he made this discovery he was so delighted that he danced about the room, and was too excited to finish the experiment for some time.

He had worked too hard, and soon after this discovery he fell ill. For days all London watched for the bulletins of the young chemist’s condition. Fortunately he recovered, and in time went back to the work which was proving so invaluable for the world of science.

The Royal Institution now provided him with a voltaic battery that was four times as powerful as any that had previously been constructed. With this he made numberless chemical discoveries. The Royal Society had made him a fellow when he was twenty-five years old, and one of its secretaries when he was twenty-nine. His London lectures grew continually more popular. The Dublin Society invited him to lecture in that city, and his course at once attracted the greatest attention. He was already the scientific lion of England, but withal a very modest and unassuming lion. Cuvier said, “Davy, not yet thirty-two, in the opinion of all who could judge of such labors, held the first rank among the chemists of this or of any other age.” The National Institute of France awarded him the prize that had been established by Napoleon for the greatest discovery made by means of galvanism. Then, in 1812, when he was thirty-three, he was knighted by the Prince Regent.

Sir Humphrey Davy, as he now was, married Mrs. Appreece, a woman of many talents and unusual intelligence. She was rich, and soon after their marriage Davy was able to resign his professorship at the Royal Institution, which he had held for twelve years, and devote himself to original research and to travel. Carrying a portable chemical apparatus for his studies, Sir Humphrey and Lady Davy went first to Scotland, and then to France, Italy, and Germany. They met the most prominent men of the age in those countries. These men found the famous chemist interested in everything about him, as much of a poet as a scientist. In Rome he wrote a sonnet to the sculptor Canova, and the literary circles of Italy proclaimed him a poet after their own heart.

Davy was now one of the foremost chemists of the world, but he could as yet hardly lay claim to the title of inventor. He had been an ambitious man, and had once said that he had escaped the temptations that lay in wait for many men because of “an active mind, a deep ideal feeling of good, and a look toward future greatness.” That future greatness had always been in his thoughts, and had been one of the compelling powers in his great chemical discoveries. But beyond this thought of greatness was a very deep and earnest desire to help his fellow men. So when the chance to do this offered he took advantage of it at once.

Explosions of coal-gas were only too common in the mines of England. They were almost always fatal to the miners, and formed the greatest peril of those who labored underground. In 1812 a terrible explosion occurred in a leading English mine, and caused the death of almost a hundred miners. The mine had caught on fire, and had to be closed at the mouth, which meant certain destruction to those within. The catastrophe was so great that the biggest mine-owners met to see whether some protection against such accidents could not be devised. After much discussion they appointed a committee to call on Sir Humphrey Davy and ask him to investigate the possibilities for them.

Davy realized that here lay his opportunity to be of real service to men, the goal he had always had in mind. He took up the question, experimented with fire-damp, and found that it was in reality light carburetted hydrogen. He visited many mines, and took into careful consideration the conditions under which the men worked. For months he investigated and experimented, and at length, in 1815, he constructed what he called the safety-lamp. This was an oil lamp which had a chimney or cage of wire gauze. The gauze held the flame of the lamp from passing through and igniting the fire-damp outside. It was only possible for a very little of the fire-damp to penetrate the gauze and such as did was held harmless prisoner. The cage allowed air to pass and light to escape, and although by the combustion of the fire-damp the wire gauze might become red hot, it was still efficient as a safety-lamp.