滑石∶色白味淡，质滑而软，性凉而散。《神农本草经》谓其主身热者，以其微有解肌之力也，谓其主癃
闭者，以其饶有淡渗之力也；且滑者善通窍络，故又主女子乳难；滑而能散，故又主胃中积聚；因热小便不
利者，滑石最为要药，若寒温外感诸证，上焦燥热下焦滑泻无度，最为危险之候，可用滑石与生山药各两许，煎汤
服之，则上能清热，下能止泻，莫不随手奏效（有附案载于滋阴清燥汤下可参观）。
外感大热已退而阴亏脉数不能自复者，可于大滋真阴药中（若熟地黄、生山药、枸杞之类）少加滑石，则
外感余热不至为滋补之药逗留，仍可从小便泻出，则其病必易愈。若与甘草为末（滑石六钱，甘草一钱，名六
一散，亦名天水散）服之，善治受暑及热痢；若与赭石为末服之，善治因热吐血、衄血；若其人蕴有湿热、周
身漫肿、心腹膨胀、小便不利者，可用滑石与土狗研为散服之，小便通利肿胀自消，至内伤阴虚作热，宜用六
味地黄汤以滋阴者，亦可少加滑石以代苓、泽，则退热较速。盖滑石虽为石类，而其质甚软，无论汤剂丸散，
皆与脾胃相宜，故可加于六味汤中以代苓、泽。其渗湿之力，原可如苓、泽行熟地之滞泥，而其性凉于苓、
泽，故又善佐滋阴之品以退热也。
天水散，为河间治暑之圣药，最宜于南方暑证。因南方暑多挟湿，滑石能清热兼能利湿，又少加甘草以和
中补气（暑能伤气），是以用之最宜。若北方暑证，不必兼湿，甚或有兼燥，再当变通其方，滑石、生石膏各
半，与甘草配制，方为适宜。
滑石：颜色白、味道淡，质地滑润而柔软，药性凉而能发散。《神农本草经》说它能治疗身体发热，是因为它具有轻微的解肌（解除肌表之邪）作用；说它能治疗小便不通，是因为它富含淡渗利湿的作用；而且“滑”的特性善于通窍络，所以又能治疗妇女乳汁难下；“滑”而能散，所以又能治疗胃中的积滞肿块；如果是因热导致的小便不利，滑石是最关键的药物。如果是外感寒温病证，出现上焦燥热、下焦滑泻无度的情况，这是非常危险的证候，可以用滑石和生山药各约一两，煎汤服用，这样上面能清热，下面能止泻，没有不立刻见效的（有关案例记载在滋阴清燥汤下方，可以参考）。
如果外感大热已经退去，但阴液亏损、脉象数疾而不能自行恢复的，可以在大补真阴的药物中（如熟地黄、生山药、枸杞等）少量加入滑石，那么外感的余热就不会被滋补药物滞留，仍然可以通过小便排出，这样病情必定容易痊愈。如果将滑石与甘草研成粉末服用（滑石六钱，甘草一钱，名为六一散，也叫天水散），善于治疗中暑及热痢；如果与赭石研成粉末服用，善于治疗因热引起的吐血、鼻出血；如果患者体内蕴有湿热，全身弥漫性肿胀，心腹胀满，小便不利的，可以用滑石与土狗（蝼蛄）研为散剂服用，小便通利后肿胀自然消退。至于内伤阴虚导致的发热，适宜用六味地黄汤来滋阴的，也可以少量加入滑石以代替茯苓、泽泻，则退热速度较快。大概滑石虽然属于石类，但其质地很软，无论是汤剂还是丸散，都与脾胃相适宜，所以可以加入六味地黄汤中以代替茯苓、泽泻。它的渗湿利水之力，原本就可以像茯苓、泽泻那样消除熟地黄的滋腻停滞，且其药性比茯苓、泽泻更凉，所以又善于辅助滋阴药物来退热。
天水散，是刘河间治疗暑病的圣药，最适合南方的暑病证候。因为南方的暑气多夹杂湿气，滑石既能清热又能利湿，再加上少量甘草来调和middle气、补气（暑气会损伤元气），所以使用最为适宜。如果是北方的暑病证候，不一定兼夹湿气，甚至可能兼夹燥气，这时应当变通方剂，将滑石、生石膏各取一半，与甘草配制，才为适宜。
Talcum (Huashi): Its color is white and taste is bland; its texture is slippery and soft, and its nature is cool and dispersing. The *Shennong Bencao Jing* states that it treats body heat because it possesses a slight ability to release the muscle layer (Jieji); it states that it treats strangury (Longbi) because it has abundant power of light diuresis (Danshen). Moreover, its "slippery" quality facilitates the unblocking of orifices and collaterals, thus it also treats difficult lactation in women; its slipperiness combined with dispersing action allows it to treat accumulations and masses in the stomach. For cases of dysuria caused by heat, Talcum is the most essential herb. In cases of external contraction of cold or warm pathogens, presenting with dryness-heat in the upper jiao and profuse loose stools in the lower jiao—a most dangerous condition—one may decoct approximately one tael each of Talcum and Raw Dioscorea Rhizome (Sheng Shanyao) and administer the soup. This will clear heat above and stop diarrhea below, invariably producing immediate effects (see the case record under Ziyin Qingzao Tang for reference).
In cases where the high fever of an external contraction has subsided, yet yin deficiency and rapid pulse prevent recovery, a small amount of Talcum may be added to potent yin-nourishing herbs (such as Prepared Rehmannia Root [Shu Dihuang], Raw Dioscorea Rhizome [Sheng Shanyao], and Goji Berry [Gouqi]). This ensures that residual heat from the external contraction is not retained by the tonifying herbs but can still be excreted via urine, making the disease easier to cure. If administered as a powder mixed with Licorice Root (Liquorice) [Gancao] (six qian of Talcum and one qian of Liquorice, named Liu Yi San, also known as Tian Shui San), it effectively treats summerheat and dysentery due to heat. If taken as a powder mixed with Hematite (Zhesi), it effectively treats hematemesis and epistaxis due to heat. For patients harboring damp-heat, presenting with generalized edema, abdominal distension, and dysuria, Talcum ground together with Mole Cricket (Tugou) into a powder can be used; once urination becomes smooth, the swelling will subside spontaneously. Regarding fever due to internal injury and yin deficiency, where Liu Wei Di Huang Tang is indicated for nourishing yin, a small amount of Talcum may be added to replace Poria (Fuling) and Alisma Rhizome (Zexie), resulting in faster reduction of fever. Although Talcum belongs to the mineral category, its texture is very soft, making it suitable for the spleen and stomach whether in decoctions, pills, or powders. Therefore, it can be added to Liu Wei Di Huang Tang to replace Poria and Alisma. Its power to leach out dampness can originally eliminate the cloying stagnation of Prepared Rehmannia Root just as Poria and Alisma do, and since its nature is cooler than that of Poria and Alisma, it is excellent at assisting yin-nourishing agents to reduce fever.
Tian Shui San is the sacred medicine of Liu Hejian for treating summerheat and is most suitable for summerheat conditions in the South. Since southern summerheat often carries dampness, Talcum clears heat and promotes diuresis simultaneously, and the addition of a small amount of Liquorice harmonizes the middle and replenishes qi (as summerheat damages qi), making it highly appropriate. For summerheat conditions in the North, which may not involve dampness and might even involve dryness, the formula should be modified: using equal parts of Talcum and Gypsum Fibrosum (Sheng Shigao) prepared with Liquorice would be more suitable.