The name of ultraviolet rays came from this. In 1800, British physicist Herschel discovered invisible thermal Ray infrared rays outside the red light end of the triangular prism spectrum. At that time, German physicist Ritter (Ritte)
He is very interested in this discovery. He firmly believes that physics has bipolar symmetry. He believes that since there is invisible radiation outside the red end of the visible spectrum, then invisible radiation must also be found outside the purple end of the visible spectrum.
After continuous research, he finally had a bottle of silver chloride solution in one day in 1801.
At that time, it was known that silver chloride would decompose and precipitate silver when heated or illuminated, and the precipitated silver would be black due to small particles. Ritter (Ritte)
Just to determine the ingredients other than the seven-color light of the sunlight through silver chloride, he dipped a little silver chloride solution with a piece of paper and placed the paper on the outside of the purple light of the seven-color light after the white light was dispersed by the prism.
After a while, he indeed observed that the paper with silver chloride on it turned black, which showed that this part of the paper was irradiated by an invisible ray. Ritter called the invisible light near the purple light; Deoxygenated rays are emphasized as chemical reactions.
Soon after, the noun was simplified;
Chemical light, and became a well-known term at that time.
Until 1802, chemical light was finally renamed; Ultraviolet rays, the word has been used to this day.