In his earlier discoveries in compressing gases into liquids, he obtained from one thousand cubic feet of coal gas one gallon of fluid from which he distilled benzine. In 1845 the chemist Hofman found this same substance in coal-tar, from which come our beautiful aniline dyes.
After eighteen years of studying the wonderful results of Galvani's discovery at the University of Bologna, that the legs of a dead frog contract under the electric current; and of Volta, in 1799, with his voltaic pile of copper, zinc, and leather, in salt-water; and of Christian Oersted at the University of Copenhagen; and Ampère and Arago, that electricity will produce magnets, Faraday made the great discovery of magneto-electricity,—that magnets will produce electricity. At once magneto-electric machines were made for generating electricity for the electric light, electro-plating, etc. This discovery, says Professor Tyndall, "is the greatest experimental result ever attained by an investigator, the Mont Blanc of Faraday's achievements."
Soon after he made another great discovery, that of electric induction, or that one electric current will induce another current in an adjoining wire. Others had suspected this, but had sought in vain to prove it. The Bell telephone, which Sir William Thompson calls "the wonder of wonders," depends upon this principle. Here no battery is required; for the vibration of a thin iron plate is made to generate the currents. After this, Faraday proved that the various kinds of electricity are identical; and that the electricity of the Voltaic pile is produced by chemical action, and not by contact of metals, as Volta had supposed. The world meantime had showered honors upon the great scientist. Great Britain had made him her idol. The Cambridge Philosophical Society, the Institution of Civil Engineers, of British Architects, of Philosophy and of Medicine, and the leading associations of Scotland had made him an honorary member. Paris had elected him corresponding member of all her great societies. St. Petersburg, Copenhagen, Stockholm, Berlin, Palermo, Modena, Lisbon, Heidelberg, Frankfort, and our own Boston and Philadelphia had sent tokens of admiration. Eminent men from all the world came to see him.
How proud his mother must have felt at this wonderful success! She was not able to enter into her son's pursuits from lack of early education; but she talked much about him, calling him ever, "my Michael"; and would do nothing whatever without his advice. He supported her in her declining years; and she seemed perfectly happy. His father had died in his boyhood; but Faraday ever honored his occupation. He used to say, "I love a smith-shop, and anything relating to smithing. My father was a blacksmith."
He was now forty-nine. The overtaxed brain refused to work longer. Memory was losing her grasp, and but for the sweet and careful presence of Sarah Faraday, the life-work would doubtless have been finished at this time. She took him to Switzerland, where he walked beside the lakes and over the mountains with "my companion, dear wife, and partner in all things." For four years he made scarcely any experiments in original research, and then the tired brain seemed to regain its wonted power, and go on to other discoveries.
An Italian philosopher, Morichini, was the first to announce the magnetizing power of the solar rays. Mrs. Somerville covered one-half of a sewing-needle with paper, and exposed the other half to the violet rays. In two hours the exposed end had acquired magnetism. Faraday, by long and difficult experiments, showed the converse of this: he magnetized a ray of light,—an experiment "high, beautiful, and alone," says Mr. Tyndall. He also showed the magnetic condition of all matter.
He was always at work. He entered the laboratory in the morning, and often worked till eleven at night, hardly stopping for his meals. He seldom went into society, for time was too precious. If he needed a change, he read aloud Shakspeare, Byron, or Macaulay to his wife in the evening, or corresponded with Herschel, Humboldt, and other great men. In the midst of exhausting labors he often preached on the Sabbath, believing more earnestly in the word of God the more he studied science.
When he was sixty-four the great brain began to show signs of decline. Belgium, Munich, Vienna, Madrid, Rome, Naples, Turin, Rotterdam, Upsala, Lombardy, and Moscow had sent him medals, or made him a member of their famous societies. Napoleon III. made him commander of the Legion of Honor, a rare title; and the French exhibition awarded him the grand medal of honor. The Queen asked him to dine with her at Windsor Castle, and, at the request of Prince Albert her husband, she presented him with a lovely home at Hampton Court.
At seventy-one he wrote to Mrs. Faraday from Glasgow, "My head is full, and my heart also; but my recollection rapidly fails. You will have to resume your old function of being a pillow to my mind, and a rest,—a happy-making wife." Still he continued to make able reports to the government on lighthouses, electric machines, steam-engines, and the like.
And then for two years the memory grew weaker, the body feebler, and he was, as he told a friend, "just waiting." He died in his chair in his study, August 25th, 1867, and was buried in Highgate Cemetery. Westminster Abbey would have opened her doors to him, but he requested to be buried "in the simplest earthly place, with a gravestone of the most ordinary kind." On a plain marble slab in the midst of clustering ivy are his name and the dates of his birth and death. One feels a strange tenderness of heart as he stands beside this sacred spot where rests one, who, though elected to seventy societies, and offered nearly one hundred titles and tokens of honor, said he "would remain plain Michael Faraday to the last."