Mercury-in-glass thermometer ushered in a new era of accuracy and precision in thermometry, and is still to this day regarded as one of the most accurate thermometers available. The thermometer was used by the originators of the Fahrenheit and Celsius scales. Anders Celsius, a Swedish scientist, devised the Celsius scale, which was described in his publication "The origin of the Celsius temperature scale" in 1742. Celsius used two fixed points in his scale: the temperature of melting ice and the temperature of boiling water. This wasn't a new idea, since Isaac Newton was already working on something similar. The distinction of Celsius
Kodaikanal mercury poisoning in Kodaikanal originated at a thermometer factory that was owned by Hindustan Unilever. Unilever acquired the thermometer factory from cosmetics maker Pond's India Ltd. Pond's moved the factory from the United States to India in 1982 after the plant owned there by its parent, Chesebrough-Pond's, had to be dismantled following increased awareness in developed countries of polluting industries. In 1987, Pond's India and the thermometer factory went to Hindustan Unilever when it acquired Cheseborough-Pond's globally. The factory imported mercury from the United States, and exported finished thermometers to markets in the United States and Europe. Around 2001, a number of