《服石论》云∶紫雪疗香港脚毒，遍身烦热，口 ，口中生疮，狂易叫走。并解诸石草散
药热毒发，猝热黄胆，瘴疫，毒疠，猝死，温疟，五尸，五注；心腹诸疾，绞刺痛，蛊毒，
鬼魅，野道尸，骨蒸热毒，诸热风，时行疫气，小儿热惊痫，利血，诸热毒肿疠子，一切热，
主之尤良。
病者强人一服二分三分，和水服之；小、老、弱人或热毒微者，服之以意减少；香港脚病
经服石药发，热毒闷者，服之如神，水和四分服之。（以上《极要方》。）
若香港脚冲心，取一小两和水饮之。若心战冲取半小两令消已，水下亦得。若有风痫，时
时服之如前理丹石。若丹发头痛身体急或寒热不能饮食，即取一两加少芒硝和水饮之。若热
痢，亦如前。若天行热病，亦如前。若欲痢者，加之一倍，空腹服之。若邪气者，渐渐服即
并可也。《鉴真方》。
今按∶今世以此药二分当红雪一两，又依如《外台方》，可服大一两。
《服石论》云∶五石凌，食后以蜜水一杯，服方寸匕，大热者加至二匕。患热病黄者，
服三匕即愈。初得热病，服二匕亦（立）愈。无禁忌。
私记云∶治一切热病及服金石散动闷乱热困者，以水一杯，服方寸匕，大热者，加至二
匕。
今按∶今人或三两，或四两，水服之，吉。
*Fu Shi Lun* (Treatise on Taking Minerals) states: Zi Xue (Purple Snow) treats Hong Jiao Jiao (Gouty swelling and ulceration of the feet) toxicity, generalized irritability and heat, dry mouth, oral ulcers, mania with shouting and running. It also resolves heat-toxin eruptions caused by various mineral powders and herbal granules, sudden jaundice, miasma epidemics, severe pestilence, sudden death, warm malaria, Wu Shi (Five Corpse Diseases), Wu Zhu (Five Leaking Diseases); various disorders of the heart and abdomen, cramping and stabbing pain, Gu Du (Gu poison), demonic influences, wild Dao corpse toxins, bone-steaming heat-toxin, various wind-heat disorders, seasonal epidemic qi, pediatric heat-induced convulsions and epilepsy, bloody stool, various heat-toxin swellings and leprosy-like lesions, and all heat conditions; it is especially excellent for treating these.
For patients with strong constitutions, take 2 fen or 3 fen per dose, mixed with water and swallowed; for children, the elderly, the weak, or those with mild heat-toxin, reduce the dosage according to circumstances; if Hong Jiao Jiao triggered by taking mineral drugs causes severe heat-toxin oppression, taking this medicine acts miraculously, taken with 4 fen of water dissolved. (Above from *Ji Yao Fang*.)
If Hong Jiao Jiao toxin rushes to the heart, take one small liang, mix with water and drink. If there is heart tremor and rushing evil qi, take half a small liang, allow it to dissolve, and swallow with water. If there is wind-epilepsy, take it regularly as previously described for regulating Dan Shi (cinnabar and stone) medicines. If Dan Shi eruption causes headache, body stiffness, alternating chills and fever, or inability to eat and drink, take one liang, add a small amount of Mang Xiao (Mirabilite), mix with water and drink. If there is heat-dysentery, follow the previous method. If there is Tian Xing Re Bing (seasonal epidemic heat disease), follow the previous method. If purgation is desired to expel toxins, double the dose and take on an empty stomach. If there is evil qi influence, take it gradually, which is acceptable. From *Jian Zhen Fang*.
Current verification: In modern times, two fen of this medicine is considered equivalent to one liang of Hong Xue (Red Snow). Furthermore, following *Wai Tai Mi Yao*, one may take one large liang.
*Fu Shi Lun* states: Wu Shi Ling, after meals, take one Fang Cun Bi (a square-inch measure scoop) with a cup of honey-water; for severe heat, increase to two scoops. For those suffering from heat disease with jaundice, taking three scoops leads to recovery. For newly contracted heat disease, taking two scoops also leads to immediate recovery. There are no contraindications.
Private records state: To treat all heat diseases and cases where taking mineral/granule powders causes agitation, oppression, confusion, and heat exhaustion, use one cup of water, take one Fang Cun Bi; for severe heat, increase to two scoops.
Current verification: Some people today take three or four liang, swallowed with water, which is auspicious.