| Experimental researches in electricity | |
| 1839 |  |
| Michael Faraday(1791-1867) | |
|
Michael Faraday was undoubtedly the greatest experimental scientist throughout the whole history of science. In spite of his humble birth, Faraday educated himself through his keen interest in science and managed to become an apprentice to a bookbinder. There he had access to many scientific books which came into the shop. Faraday later succeeded in becoming an assistant to Sir Davy, a leading English chemist, who became the chairman of the Royal Society and thus started his course of study in chemistry as one of Davy’s pupils. While studying Davy’s methods, Faraday coined the word “electrolysis,” as well as the terms, “electrolyte,” “electrode,” “anode,” “cathode,” “anion” and “cation”. He also made several major contributions such as the liquefaction of gases and the discovery of benzene. In addition to that Faraday succeeded Davy in his electro-chemical studies and developed the field. Faraday’s greatest contribution to this field was the establishment of the law of electrolysis, known as Faraday’s law. In this law, the mass of deposit on the electrode is proportional to the quantity of electricity which flows through the electrolyte. The mass of deposited matter obtained with a fixed quantity of electricity is in proportion to the atomic weight of the element of deposit and is in inverse proportion to the valency of that. With this achievement, Faraday founded the field of modern electrochemistry and thus the unit that measures the quantity of electricity in electrolysis is named after him in honor of that contribution. Inspired by Oersted’s discovery that the compass needle was rotated by an electric current, Faraday made another important contribution with the discovery and application of electromagnetic induction. Aware that an electric flow produces a magnetic force, he devised an apparatus in which a wire was rotated around a fixed magnet as the wire was electrified. The magnet was rotated around the fixed conductor as it was electrified. With this, Faraday succeeded in transforming electric and magnetic forces into a mechanical force, thus inventing the electromotor. Subsequently, in contrast to this, he intended to produce an electric flow by magnetic force. At the outset, he devised an iron ring which was coiled with wire in two parts independently, and charged only one coil with electricity. He observed that the electric flow was generated in the other coil only at the very moment the electricity was turned on and off. Faraday concluded that the electricity was generated when the coil was cut transversely with the line of magnetic force at the moment it spread out or extinguished. He thus invented the transformer and with that initiated the field theory of force. Faraday next succeeded in obtaining the same results when the magnet moved through the coil instead of using an electro-magnet. Finally, he devised an apparatus in which a round plate rotated between two magnets, and succeeded in getting a continuous electric current from the rotating plate. The apparatus, anticipated by Arago, a French scientist, in his application of Oersted’s experiment, was completely rearranged and innovated by Faraday. With this he established the induction of electricity and invented a generator which could convert mechanical power into electric power and could supply a continuous amount of electricity. Moreover, he discovered that polarized light is affected by a magnetic field, and experimentally showed that electro-magnetism has a close relation with the light, ideas that were developed further by Maxwell’s later advances. Faraday was proposed for membership in the Royal Society in 1824, read many papers on the above mentioned results, and published these in the society’s Philosophical Transactions. This book is his magnum opus which brought together those and other papers presented by him. It is no exaggeration to say that all modern industries and technologies were made possible by Faraday’s contributions. |
