Snails, also known as tu niu er and tian luo si, are mentioned in the book "Ming Yi Bie Lu". They belong to the family Bradybaenidae, including the species Bradybaena similaris (Freussde) and Cathaica fasciola (Draparnaud), as well as other closely related species in the same family. Snails are captured in the summer and autumn, kept in a quiet environment to allow them to excrete feces, then cleaned, scalded with boiling water, and dried.
Processing method:
1. According to the book "San Yin Fang" and "Yi Zong Shuo Yue", snails are dried by stringing them on bamboo skewers and placing them on a roof. In modern practice, the raw medicinal material is cleaned, removing impurities, and then dried. It can be crushed or ground into powder when needed.
2. According to the book "Yi Xue Gang Mu" and "Xian Xing Zhai Guang Bi Ji", snails are pierced with bamboo sticks, dried on a roof, and then burned to ash. The ash is finely ground. In modern practice, clean snails are placed in a calcining furnace, heated until they turn red, then taken out and cooled.
Appearance of the medicinal material:
Snails are spiral-shaped and flat, with their entire body retracted into the shell. They vary in size and have a light brown or grayish-white color with a glossy, semi-transparent surface. The shell is thin and easily broken, and the inner shell is milky white when crushed. Calcined snails have a snail-like appearance but are mostly broken, with a loss of gloss and a grayish-white color. They have a crispy texture and are easily broken.
Processing function:
Snails have a cool and slightly toxic nature. They enter the bladder, stomach, and large intestine meridians. They have the functions of clearing heat, calming convulsions, reducing swelling, and detoxifying. They are used for wind-heat induced epilepsy, excessive thirst, throat obstruction, mumps, scrofula, abscesses, hemorrhoids, and prolapse of the anus. For treating excessive thirst, it can be used alone or in combination with clam powder, gentian grass, etc. (from "Tai Ping Sheng Hui Fang"). For treating wind-induced epilepsy, it can be combined with centipedes, scorpions, cinnabar, etc. (from "Shandong Medicinal Animals"). Other examples include snail ointment for treating hemorrhoids (from "Ji Sheng Fang") and snail powder for treating scrofula (from "San Yin Fang"). It can be used raw, but after calcination, its cold nature is reduced, making it easier for formulation.
