Gu () or jincan () was a venom-based poison associated with cultures of south China, particularly Nanyue. The traditional preparation of gu poison involved sealing several venomous creatures (e.g., centipede, snake, scorpion) inside a closed container, where they devoured one another and allegedly concentrated their toxins into a single survivor, whose body would be fed upon by larvae until consumed. The last surviving larva held the complex poison. Gu was used in black magic practices such as manipulating sexual partners, creating malignant diseases, and causing death. According to Chinese folklore, a gu spirit could transform into various animals, typically a worm, caterpillar, snake, frog, dog, or pig.
Names
Circa 14th-century BCE Shang dynasty oracle inscriptions recorded the name gu, while 7th-century CE Tang dynasty texts first used jincan "gold silkworm".
Gu
The term gu , says Loewe, "can be traced from the oracle bones until modern times, and has acquired a large number of meanings or connotations". Before discussing gu, it is necessary to introduce the related word chong "wug".
Chong or (originally a "snake; worm" pictogram) "insect; bug; pest; worm; spider; amphibian; reptile; dragon; etc." denotes a Chinese folk taxonomy lacking an adequate English translation equivalent. Carr proposes translating chong as "wug" – Brown's portmanteau word (from worm + bug) bridging the lexical gap for the linguistically widespread "class of miscellaneous animals including insects, spiders, and small reptiles and amphibians". Contrast the Wug test for investigating language acquisition of plurals in English morphology. Note that "wug" will translate chong below.
The Traditional Chinese character and the Simplified for gu "demonic poison" are "wugs inside a container" ideograms that combine chong or "wug" and min "jar; cup; dish; utensil". Early written forms of gu range from (c. 14th–11th centuries BCE) Oracle bone script to (c. 3rd century BCE) Seal script characters. The Oracle characters had two or one "wug" elements inside a container, while the Seal characters had three. Shima's concordance of oracle bone inscriptions lists 23 occurrences of gu written with two wugs and 4 with one; many contexts are divinations about sickness. Marshall concludes, "The oracle-bone character of gu is used to refer to the evil power of the ancestors to cause illness in the living."
Jincan
Jincan "gold silkworm/caterpillar" is a gu synonym first recorded in the Tang dynasty. Li Xian's (7th century) commentary to the Hou Han Shu uses jincan as the name of a funerary decoration cast from gold, and the (9th century) author Su E describes it as a legendary golden-color caterpillar from Kashmir.
Eberhard (cf. 153) connects gu, jincan, and other love charms with the Duanwu Festival that occurs on the fifth day of the fifth month in the Chinese calendar, which is "the theoretical apogee of summer heat". Among the Miao on the fifth of the fifth month poisonous animals were put into a pot and allowed to devour each other, and they were called 'gold-silkworms'. The more people were killed by the ku, the richer the kus owner became. In our time the normal term for ku has been 'gold-silkworm'. These animals can make gold. It was typical for the gold-silkworm that people continued to feed this animal in the pot, that humans had to be sacrificed to it, that the animal kept the house clean and worked for its master like a brownie, but that it caused harm to its master if he did not provide proper sacrifices. "For centuries, the Miao, particularly Miao women," writes Schein, "have been feared for their mastery of the so-called gu poison, which is said to inflict death from a distance with excruciating slowness."
Groot quotes a Song dynasty description. a gold caterpillar is a caterpillar with a gold colour, which is fed with silk from Shuh (Szĕ-ch‘wen). Its ordure, put in food or drink, poisons those who take it, causing certain death. It can draw towards a man the possessions of such victims, and thus make him enormously rich. It is extremely difficult to get rid of it, for even water, fire, weapons or swords can do it no harm. Usually the owner for this purpose puts some gold or silver into a basket, places the caterpillar also therein, and throws the basket away in a corner of the street, where someone may pick it up and take it with him. He is then said to have given his gold caterpillar in marriage.