The name of this product sounds like a mispronounciation of "pour some on," which seems appropriate enough and is easy to remember it by. But, this is the Cantonese for what is called in mandarin Bao Xin An or "Protect the Heart's Peace" oil. It is a famous product of Hong Kong, produced at the Po Sum On Medicine Factory, that relies on more than 50 employees to supply world demand. The company was established in 1907 specifically to produce this oil. Po Sum On won the British Empire Exhibition Certificate in 1924, and was distributed in mainland China, Taiwan, and Macao by the 1930s. It has been one of the leading topical oils from the Chinese tradition, with many imitations. Po Sum On is an example of a warming liniment for the circulation, yet it has an anti-inflammatory effect for the skin. It is considerably thicker and darker in hue than the thin, clear white flower oil that is also quite popular. Po Sum On is used to treat joint and muscle aches, used for osteoarthritis, neuralgia, and traumatic injuries (sprains).