Ice slice, also known as Longnao, Meihua Ice Slice, and Meipian, is a naturally occurring crystalline compound derived from the resin of the Dragon Brain Fragrant tree (Dryobalanops aromatica Gaertn.f.) in the Dragon Brain Fragrant family. It mainly contains the dextrogyrate borneol, which is extracted from the cracks of the Dragon Brain Fragrant tree trunk and processed from the dried resin. Alternatively, the trunk and branches can be cut into pieces, steam distilled to sublime, and then cooled to form crystals.
[Processing Method] "Crush into fine powder" in "Tai Ping Sheng Hui Fang". "Gently grind in an old porcelain bowl. If done quickly, the bowl will become hot and the fragrance will dissipate." Currently, the original medicinal material is taken and impurities are removed. When used, it is ground into powder.
[Characteristics of the Herbal Medicine] It is a translucent or colorless crystal that is white or grayish-white. It is in the form of polygonal flakes or granules. It has a soft and brittle texture, a fragrant aroma, and a spicy and cool taste. It slowly dissolves when chewed. It is volatile and produces dense smoke and a flame with a light when burned.
[Quality Requirements] ① Take 2.5g of the herbal medicine, add 25ml of water, shake well, filter, and take two portions of the filtrate, each with 10ml. Add 2 drops of methyl red indicator to one portion and 2 drops of phenolphthalein indicator to the other portion. Neither should turn red. ② The non-volatile content should not exceed 0.035%. ③ Take 1g of the herbal medicine, add 10ml of petroleum ether, shake to dissolve, and the solution should be clear. ④ The heavy metal content should not exceed 0.00005%. The arsenic salt content should not exceed 0.00002%. ⑤ The content of borneol (C10H18O) should not be less than 55.0%.
[Processing Functions] Ice slice has a spicy and bitter taste and a slightly cold nature. It belongs to the heart and lung meridians. It has the functions of opening the orifices, awakening the mind, clearing heat, and relieving pain. It is used for conditions such as heat-induced coma, convulsions, wind-stroke with phlegm convulsions, sudden onset of qi stagnation, coma due to internal heat, red eyes, mouth ulcers, sore throat, and ear canal discharge. For example, it is used in the Kaisuan San for sudden wind-stroke with blindness and lockjaw (from "Sheng Ji Zong Lu"); in the Bing Borax San for treating long-standing swelling and pain in the throat and mouth (from "Wai Ke Zheng Zong"); in the Bing Mei Wan for treating phlegm obstruction in the throat and inability to spit out phlegm (from "Qu Jing Hui Jie"); in the Longnao Gao for treating red and painful eyes with sudden onset of white opacity (from "Tai Ping Sheng Hui Fang"); in the Heiling Dan for treating carbuncles with yellow discharge and itching (from "Hai Feng Yan Fang Ji"); in the Bingpian Mangxiaosan for treating infections in surgery (from "Journal of Integrated Traditional Chinese and Western Medicine, 1986"); and in the Bingshewan San for treating acute purulent otitis media (from "Journal of Traditional Chinese Medicine and Pharmacy, 1986"). After being purified and ground, the herbal medicine can improve the cleanliness of the medicine, facilitate the exertion of therapeutic effects, and aid in the adjustment and preparation of formulations.
