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Introduction
Published in Ahmad Shahid Khan, Saurabh Kumar Mukerji, Electromagnetic Fields, 2020
Ahmad Shahid Khan, Saurabh Kumar Mukerji
The concept of static electricity is not a new one. The ability of rubbed amber to attract light particles was recorded in 600 bce by the Greek thinker Thales of Miletus. For nearly 2,000 years, this concept remained almost confined to history. Then in 1296 ce, a magnetic compass was reportedly brought to Venice from the court of Kublai Khan by Marco Polo. In 1600 an English scientist, William Gilbert, demonstrated the effect on a compass of a metalized sphere (similar to earth), and published De Magnete. The word “electricity” was first used by Sir Thomas Browne in 1646 and the first electrostatic machine was reportedly built by Otto Von Guericke in 1650. In 1733 Charles Du Fay discovered two kinds of charges, which he called positive and negative. He also noted the attraction and repulsion of unlike and like charged particles. In 1735 conducting and dielectric properties were demonstrated by Stephen Grey. In 1745 the Leyden jar, the first capacitor, was invented by E. J. G. Von Kleist and P. V. Musschenbrock independently. In 1746 Benjamin Franklin classified electricity into negative (excess of electrons) and positive (deficiency of electrons). He also demonstrated the electrical nature of lightning and invented the lightning conductor in 1752. In 1787, M. Lammond invented the telegraph. In 1790 Alessandro Volta found that the chemistry acting on two dissimilar metals generates electricity, and in 1800 he invented the voltaic pile battery.
Batteries
Published in Ranjan Vepa, Electric Aircraft Dynamics, 2020
Batteries have a fascinating history. In the year 1800, the Italian Alessandro Volta invented the so-called Voltaic pile, using silver and zinc plates separated by leather moistened with brine or vinegar, which functioned as a single electric cell providing a current to an external circuit. In 1836, John Frederic Daniell, a British chemist and meteorologist, invented the Daniell cell, which was a copper pot filled with copper sulfate solution, into which was immersed an unglazed earthenware container filled with sulfuric acid and a zinc electrode. The copper electrode acted as the cathode while the zinc electrode was the anode and the unglazed earthenware provided a salt bridge between the copper sulfate solution and the sulfuric acid. The purpose of a salt bridge, connecting the two “half cells” was to prevent electron movement (not ions) in the electrolyte and to maintain charge balance. The principle of the Daniell cell is illustrated in Figure 3.1. In 1859, the Frenchman Gaston Planté constructed the first rechargeable lead-acid cell. In 1868, another Frenchman Georges Leclanché assembled the first carbon-zinc wet cell, which was followed in 1888 by Carl Gassner’s invention of the carbon-zinc dry cell. It was in 1898, that the first commercial flashlight cell, now commonly known as the “D cell” was invented, and the very next year, Waldemar Junger invented the nickel-cadmium cell.
Robert Hare's Theory of Galvanism: A Study of Heat and Electricity in Early Nineteenth-Century American Chemistry
Published in Ambix, 2018
Hare’s interest, in part, stemmed from developments in Europe. Extending William Nicholson and Anthony Carlisle’s investigations of the chemical effects associated with the electrical action of the voltaic pile – an instrument composed in its simplest form of layered units of disks of zinc, brined cardboard, and silver – Humphry Davy showed that applying the pile’s current to liquids and other materials caused their chemical decomposition and led to the isolation of new elements, such as potassium (1807), sodium (1807), and chlorine (1810).31 Moreover, he discovered that substances formed at the wires connected to the positive or negative end of the battery. For example, as water decomposed, hydrogen gas formed only at the negative end and oxygen gas at the positive end.32 This suggested first to Davy and later to Berzelius that different materials possessed different electrical properties. More specifically, Davy and Berzelius identified two new categories of materials: electronegative substances (i.e. materials attracted to the positively charged end of the pile), which included oxygen, antimony, arsenic, chromium, oxymuriatic acid (chlorine), and selenium, and electropositive materials (i.e. materials attracted to the negatively charged end of the pile), which included hydrogen, cobalt, platinum, potassium, silver, and sodium.33