《考工记》云∶橘逾淮而北为枳。盖橘得江南温热之气，故气味辛温，能达中土之气，通灌于四旁∶枳
乘江北寒凉之气，性味苦寒，能去寒热之邪下泄。是一物而性不同，因天地之气也。本经主大风在皮肤中，
如麻豆苦痒者，能启寒水之发，以对待其阳邪。（枳叶经
冬不凋。得寒水之气。）夫橘至成熟而后采摘，天气充满，故能横遍于四体；枳乃初生之小者，其气收敛，故专生下
泄。若夫枳壳之苦泄，其性又能横充，所以本经止云实而无壳，至宋时，始有壳、实之分。如病胸腹实而
当下者，应用实，而以壳代之，乃识见浅而无力量处。
橘皮臭香色黄，味甘而带辛，甘、香、黄主土，辛主金。夫胃土主脉络，（胃又属阳明，秋金其色白。）脾土主肌
肉，肺金主皮毛，橘皮在内之白膜，如胃腑所主之络脉，皮内之白若肌肉，皮外之宗眼如毛孔，是从中达
外，由脉而络，络而肌，肌而皮也。橘皮能宣发阳明之汗，解胃气之逆呃，盖能宣达胃气，外出于皮毛，
若夫皮腠之邪，逆于内而为喘急，膈上之痰，结于上而为咳嗽，欲消痰降气而从下解者，是又从肌而络，
络而脉，脉而胃也。是邪正之气，欲出欲入，而用橘皮为导引者，皆藉皮内之白膜，如去其膜白，则断截
出入之道路，故本经止曰橘皮，而并无留白、去白之分。
《考工记》中说：橘子越过淮河以北就变成枳。这是因为橘子得到江南温热的气候，所以气味辛温，能够通达中焦脾胃之气，并灌注到四肢百骸；枳则承受江北寒凉的气候，性味苦寒，能够驱除寒热邪气并向下排泄。这是同一种植物而性质不同，是因为天地气候差异所致。《神农本草经》记载枳实主治大风在皮肤中，像麻豆一样令人痛苦瘙痒的症状，它能激发寒水之气的生发，以对抗阳邪。（枳树叶经过冬天也不凋落，说明它得到了寒水之气。）橘子要等到成熟后才采摘，此时天气充满生机，所以药力能横遍于四肢；枳则是初生的小果实，其气收敛，所以专门作用于下焦并向下排泄。至于枳壳的苦泄作用，其药性又能横向充达，所以《本经》只提到“实”而没有提到“壳”，直到宋代，才开始有枳壳和枳实的区分。如果病症是胸腹结实需要攻下的，应当使用枳实，如果用枳壳来代替，那就是见识浅薄且用药不得力的表现。
橘皮气味芳香，颜色发黄，味道甘甜而带有辛味。甘、香、黄属性属土，辛属性属金。胃土主管脉络（胃又属于阳明经，秋金的颜色是白色），脾土主管肌肉，肺金主管皮毛。橘皮内部白色的膜，就像胃腑所主管的络脉；橘皮内侧白色的部分就像肌肉；橘皮外表面的毛孔就像皮毛。这是由内达外，从经脉到络脉，从络脉到肌肉，从肌肉到皮毛的过程。橘皮能够宣发阳明经的汗液，解除胃气上逆引起的呃逆，因为它能宣通胃气，使之外出于皮毛。如果是腠理之间的邪气，逆乱于内导致喘急，或者膈膜以上的痰饮，结聚于上导致咳嗽，想要通过消痰降气而从下部解决时，这就是从肌肉到络脉，从络脉到经脉，从经脉到胃的过程。无论是邪气正气欲出还是欲入，使用橘皮作为引导，都是借助橘皮内部的白色膜作为通道。如果去除了橘皮内部的白膜，就截断了出入的道路，所以《本经》只称为“橘皮”，并没有保留白膜或去除白膜的区分。
The *Kaogong Ji* (Record of Examination of Craftsman Skills) states: "When oranges cross the Huai River to the north, they become trifoliate orange." This is because the orange receives the warm and hot qi of Jiangnan, thus its aroma and flavor are pungent and warm, capable of reaching the qi of the central earth (spleen and stomach), and irrigating the four extremities. The trifoliate orange (Zhi Shi) bears the cold and cool qi of Jiangbei; its nature and flavor are bitter and cold, capable of expelling pathogenic cold and heat downwards. It is one substance with different natures due to the qi of heaven and earth. The *Shennong Bencao Jing* (Divine Farmer's Materia Medica) records that it governs severe wind in the skin, causing itching like hemp seeds or bitter beans; it can initiate the emergence of cold water qi to counteract yang pathogens. (Trifoliate orange leaves do not fall in winter, indicating they have obtained the qi of cold water.) Oranges are harvested only after ripening, when heavenly qi is full, so their action spreads horizontally across the four limbs. Trifoliate orange fruits are immature and small; their qi is astringent, so they specifically descend and drain downwards. Regarding the bitter draining property of Zhi Qiao (Immature Bitter Orange Peel), its nature can also expand horizontally. Therefore, the *Bencao Jing* mentions only the fruit (Shi) and not the peel (Qiao). It was not until the Song Dynasty that a distinction between Qiao and Shi was made. If the disease involves solid accumulation in the chest and abdomen requiring purgation, one should use Shi (the fruit); using Qiao as a substitute indicates superficial understanding and lack of efficacy.
Ju Pi (Tangerine Peel) has an aromatic odor, yellow color, sweet taste with a hint of pungency. Sweetness, aroma, and yellow color belong to Earth; pungency belongs to Metal. Stomach Earth governs the collaterals (the Stomach also belongs to the Yangming channel, and Autumn Metal is white); Spleen Earth governs muscles; Lung Metal governs the skin and hair. The white membrane inside Ju Pi resembles the collaterals governed by the Stomach; the white part inside the peel resembles muscle; the pores on the outer surface resemble the skin. This represents a pathway from the interior to the exterior, from channels to collaterals, from collaterals to muscles, and from muscles to skin. Ju Pi can disseminate sweat from the Yangming channel and resolve rebellious Stomach Qi causing hiccups, as it can promote the flow of Stomach Qi outward to the skin and hair. If pathogenic factors in the couli (skin and interstices) rebel inward causing wheezing and urgency, or phlegm above the diaphragm accumulates upward causing coughing, and one wishes to resolve phlegm and direct Qi downward, this follows the reverse path: from muscles to collaterals, from collaterals to channels, and from channels to the Stomach. Whether pathogenic or righteous Qi desires to exit or enter, using Ju Pi as a guide relies on the internal white membrane. If this white membrane is removed, the pathway for entry and exit is severed. Therefore, the *Bencao Jing* refers only to "Ju Pi" without distinguishing between retaining or removing the white pith.