Illustration of warm spring water from Shiwu bencao (Materia dietetica), a dietetic herbal in four volumes dating from the Ming period (1368-1644). The identity of the author and artists is unknown. It contains entries on over 300 medicinal substances and is illustrated by almost 500 paintings in colour.
The illustration depicts warm spring water flowing from a location high in the mountains. Two men are bathing in a pool fed by the spring.
The text states: Warm spring water is hot in thermostatic character and poisonous, and should on no account be drunk. Some people believe that there is sulphur beneath warm water springs, which is why the water is hot. The hottest warm-water springs are close to boiling point, and can be used to scald the carcasses of pigs and sheep. Warm springs are effective against obstinate wind impediment (fengbi), which can be alleviated by bathing in the water. There is a lake fed by a warm spring at the foot of Lushan mountain; healers tell patients suffering from scabies (jielai) and 'red bayberry sores' (yangmeichuang, syphilis) to soak in the water on a full stomach, remaining there until they are sweating. Approximately ten days after bathing in this fashion, the lesions will clear up spontaneously. However, those suffering from physical insufficiency and debility must exercise caution in bathing in this water.
