Thermometer 1665 Christiaan Huygens (1629–1695) suggested using the melting and boiling points of water as standards, and in 1694 Carlo Renaldini (1615–1698) proposed using them as fixed points on a universal scale. In 1701, Isaac Newton (1642–1726/27) proposed a scale of 12 degrees between the melting point of ice and body temperature. In 1714 Dutch scientist and inventor Daniel Gabriel Fahrenheit invented the first reliable thermometer, using mercury instead of alcohol and water mixtures. In 1724 he proposed a temperature scale which now (slightly adjusted) bears his name. He could do this because he manufactured thermometers, using mercury (which has a
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