2,637 Years of Physics from Thales of Miletos to the Modern Era. Sheldon Cohen

       As was typical of the physician scientists of the times, (see above), he held many interests, and Gilbert furthered the study of magnetism when he proposed that the entire earth was a large magnet with a North and South Pole. His book, De Magnete, published in 1600, became the standard upon which all work in magnetism was measured. It remains one of the classics of natural philosophic literature.

       In addition, Gilbert advanced the work of Thales of Miletos, and Theophrastus when he discovered that more materials could be “electrified” when rubbed with a cloth. He called these materials “electricians” and he proposed the word “electricity,” from the Latin word, electrum, for amber. He also theorized that electricity was due to the existence of a fluid surrounding an electrified body and the act of electrification was due to the passage of this fluid into the electrician. He also suggested that this fluid transfer was made possible when the friction of rubbing created the heat necessary to promote this passage.

       Although both the rubbed amber and magnetism were attractive forces, Gilbert was the first scientist to explain the difference between magnetism and the amber effect---static electricity. The term static would not enter the physicists vocabulary for two hundred more years or until electric currents were identified as moving charges of electricity.