John Canton (31.07.1718-22.03.1772) was an English experimental physicist and a Fellow of the Royal Society (1749). He was born in Stroud. From 1745 he ran a private school in London.
His research concerned electricity, magnetism, optics and heat. He demonstrated the electrification of air and electrification by influence (the electrification of a cylinder when a charged sphere is brought near it), and he constructed an electroscope and an electrometer (1753). He confirmed that different bodies differ in their resistance. In 1759 he established that electrification arises in tourmaline when it is cooled as well; in 1760 he found that Brazilian topaz also has the property of tourmaline; and in 1762 he showed that the electric charges that arise when tourmaline is heated are equal in magnitude and opposite in sign. He developed a method of making strong artificial magnets and was the first to make powerful artificial magnets. He improved the electrical machine (1762). He proved (1762) that water is compressible.