《月令》五月半夏生，当夏之半也。其形圆，其色白，其味辛，阳明胃腑之药也。阳明秉秋金之燥
气，半夏启一阴之气，上与戊土相合，戊癸合而化火，故阳明为燥热之腑，能化水谷之精微。天花粉别
名瑞雪，根粉洁白，气味苦寒，茎引藤蔓，能启阴液，从脉络而上滋于秋金，（藤蔓者，走经脉。） 故有天花、
瑞雪之名。盖水阴之气，上凝于天而为雪；天花者，天雨之六花也。一起阴气于脉外，上与阳明相合，而
成火土之燥；一起阴液于脉中，天癸相合，而能滋润其燥金。是以《伤寒》、《金匮》诸方，用半夏以助阳
明之气，渴者燥热太过，即去半夏，易花粉以滋之。先圣贤立方加减，岂轻忽欤！
庭前植百合、紫苏各数茎，见百合花昼开夜合，紫苏叶朝挺暮垂，因悟草木之性，感天地阴阳之气而
为开阖者也。如春生、夏长、秋成、冬殒，四时之开阖也；昼开、夜合、朝出、暮入，一日之开阖也。是
以一岁之中有四时，一日之中有四时，而人、物应之。百合色白气平，其形象肺，能助呼吸之开阖，故主邪
气腹胀心痛，盖气行，则邪散而胀痛解矣，主利大小便者，气化则出也；主补中益气者，气之发原于中也。
苏色紫赤，枝茎空通，其气朝出暮入，有如经脉之气，昼行于阳，夜行于阴，是以苏叶能发表汗者，血
液之汗也。（白走气分，亦走血分。）枝茎能通血脉，故易思兰先生常用苏茎通十二经之关窍，治咽膈饱闷，通大小
便，止下利赤白。予亦常用香苏细茎，不切断，治反胃膈食，吐血下血，多奏奇功。盖食气入胃，散精于肝。
浊气归心，肝主血，而心主脉。血脉疏通，则食饮自化。经云∶阳络伤则吐血，阴络伤则下血。通其络
脉，使血有所归，则吐下自止。夫茜草、归、芎之类，皆能引血归经，然不若紫苏昼出夜入之行速耳！于戏，
阴阳开阖，天地之道也，进乎技矣！
《礼记·月令》记载，五月半夏生长，正值夏季的中段。它的形状是圆形的，颜色是白色的，味道是辛辣的，属于阳明胃腑的药物。阳明经秉承秋季金气的燥性，半夏能够激发一阴之气，向上与戊土（胃）相合，戊癸相合而化生火气，因此阳明成为燥热的腑，能够消化水谷的精微物质。天花粉别名瑞雪，其根粉洁白，气味苦寒，茎蔓牵引藤蔓，能够开启阴液，沿着脉络向上滋润秋金（肺），（藤蔓的特性是走窜经脉。）所以有天花、瑞雪的命名。大概是因为水的阴气，向上凝结于天空变成雪；天花，是天雨中的六瓣花。一方面在脉外提升阴气，向上与阳明相合，形成火土的燥性；另一方面在脉中提升阴液，与天癸相合，从而能滋润燥金的肺脏。因此在《伤寒论》、《金匮要略》等方书中，使用半夏来辅助阳明经的气机，如果患者口渴，说明燥热太过，就去掉半夏，改用天花粉来滋润它。先代圣贤制定方剂时的加减变化，难道是轻率疏忽的吗！
庭院前种植了几株百合和紫苏，看到百合花白天开放晚上闭合，紫苏叶早晨挺立傍晚下垂，于是领悟到草木的习性，是感应天地阴阳之气而进行开阖运动的。如春天生长、夏天繁茂、秋天成熟、冬天凋零，这是一年四季的开阖；白天开放、晚上闭合、早晨生出、傍晚收回，是一日之中的开阖。因此一年之中有四时，一日之中也有四时，人和万物都顺应这种规律。百合色白气平，形象似肺，能够辅助呼吸的开阖，所以主治邪气引起的腹胀心痛，因为气行则邪散而胀痛解除；主治大小便通利，是因为气化功能正常则排泄通畅；主治补中益气，是因为气发源于中焦。紫苏色紫赤，枝茎中空通透，其气机早晨外出傍晚回归，就像经脉之气，白天运行于阳分，夜晚运行于阴分，因此紫苏叶能够发表发汗，这是血液之汗。（白色药物走气分，也走血分。）枝茎能够疏通血脉，所以易思兰先生常用紫苏茎疏通十二经的关窍，治疗咽喉膈部饱闷，通利大小便，止住下利赤白痢。我也常用香苏的细茎，不切断，治疗反胃膈食、吐血下血，往往取得奇效。大概食物进入胃中，将精微散布于肝。浊气归于心，肝主血，而心主脉。血脉疏通，则饮食自然消化。医经说：阳络受伤则吐血，阴络受伤则下血。疏通络脉，使血液有所归依，则吐血下血自然停止。茜草、当归、川芎之类，都能引导血液回归经脉，然而不如紫苏昼出夜入的运行迅速啊！唉，阴阳的开阖，是天地的大道，这已经超越了单纯的技艺了！
The *Yueling* (Monthly Ordinances) records that Pinelliae Rhizoma (Banxia, 半夏) grows in the fifth month, which is the middle of summer. Its shape is round, its color is white, and its taste is pungent; it is a herb for the Yangming Stomach organ. The Yangming channel inherits the dryness qi of autumn metal. Banxia stimulates the qi of one yin, combining upward with Wu Earth (Stomach). When Wu and Gui combine, they transform into fire; thus, the Yangming becomes an organ of dryness and heat, capable of transforming the essence and micro-elements of food and drink. Trichosanthis Radix (Tianhuafen, 天花粉), also known as Ruixue (Auspicious Snow), has roots and powder that are pure white. Its flavor is bitter and cold. Its stems draw vine tendrils, which can initiate yin fluids and nourish autumn metal (Lung) upward along the meridians. (Vine tendrils have the characteristic of traversing the meridians.) Hence the names Tianhua (Heavenly Flower) and Ruixue. It is said that the yin qi of water condenses upward in the sky to become snow; Tianhua refers to the six-petaled flowers of heavenly rain. On one hand, it raises yin qi outside the vessels, combining upward with Yangming to form the dryness of fire and earth; on the other hand, it raises yin fluid inside the vessels, combining with Tian Gui (Heavenly Water/Reproductive Essence) to moisten the dry metal. Therefore, in formulas from the *Shanghan Lun* (Treatise on Cold Pathogenic Diseases) and *Jingui Yaolue* (Essential Prescriptions of the Golden Cabinet), Banxia is used to assist the qi of Yangming. If the patient is thirsty, indicating excessive dryness-heat, Banxia is removed and replaced with Tianhuafen to nourish. Did the sages of old make additions and subtractions to their prescriptions lightly or negligently?
In front of the courtyard, several stalks of Lilii Bulbus (Baihe, 百合) and Perillae Folium (Zisu, 紫苏) were planted. Observing that Baihe flowers open during the day and close at night, while Zisu leaves stand upright in the morning and droop in the evening, I realized that the nature of herbs involves opening and closing movements induced by the yin and yang qi of heaven and earth. Such as spring growth, summer flourishing, autumn maturity, and winter decline—these are the openings and closings of the four seasons; daytime opening, nighttime closing, morning emergence, evening return—these are the openings and closings within a single day. Thus, within a year there are four seasons, and within a day there are also four seasons, to which humans and all things respond. Baihe is white in color and neutral in qi, resembling the Lung in form, and can assist the opening and closing of respiration. Therefore, it treats abdominal distension and heart pain caused by pathogenic qi; because when qi moves, pathogens disperse and distension/pain resolves. It promotes urination and defecation because proper qi transformation leads to smooth excretion; it tonifies the middle and benefits qi because qi originates from the middle jiao. Zisu is purple-red in color, with hollow and permeable stems and branches. Its qi emerges in the morning and returns in the evening, similar to the qi of the meridians, which travels through the yang during the day and the yin at night. Therefore, Zisu leaf can release the exterior and induce sweating, producing sweat from blood/yin. (White-colored herbs traverse the qi level and also the blood level.) The stems and branches can unblock blood vessels. Thus, Mr. Yisilan often used Zisu stems to unblock the acupoints and passageways of the twelve meridians, treating fullness and oppression in the throat and diaphragm, promoting urination and defecation, and stopping dysentery with red and white discharge. I also frequently use the fine stems of Xiangsu (Fragrant Perilla), without cutting them, to treat regurgitation, food stagnation in the diaphragm, hematemesis, and lower bleeding, often achieving remarkable results. Generally, when food enters the stomach, its essence is dispersed to the Liver. Turbid qi returns to the Heart. The Liver governs blood, and the Heart governs the vessels. When the blood vessels are unblocked, food and drink are naturally digested. The classics state: Injury to the yang collaterals causes hematemesis; injury to the yin collaterals causes lower bleeding. By unblocking the collaterals, allowing blood to return to its proper course, vomiting and lower bleeding will cease naturally. Herbs such as Rubiae Radix et Rhizoma (Qiancao, 茜草), Angelicae Sinensis Radix (Danggui, 当归), and Chuanxiong Rhizoma (Chuanxiong, 川芎) can all guide blood back to the meridians, yet none match the rapid movement of Zisu emerging by day and returning by night! Alas, the opening and closing of yin and yang is the way of heaven and earth; this knowledge transcends mere technique!