经有十二，司化者六经，从化者六经。从化者不司气化，总以司化者为主，故十二经统于六气。病则或
见司化者之本气，或见从化者之本气，或司化者而见从化之气，或从化者而见司化之气，全视乎本气之衰旺
焉，手少阴以君火司化，足少阴之水从令而化热者常也。而足少阴之病寒，是从化者自见其本气，以水性原
寒。手少阴之病寒，是司化者而见从化之气，以君火原从水化也。足太阳以寒水司化，手太阳之火从令
而化寒者常也。而手太阳之病热，是从化者自见其本气，以火性原热，足太阳之病热是司化者而见从化之气
，以寒水原从火化也。足厥阴以风木司化，手厥阴之火从令而化风。手少阳
以相火司化，足少阳之木从令而化暑者常也。而手厥阴之病暑，足少阳之病风，是从化者自见其本气，以火性
生暑，而木性生风也。足太阴以湿土司化，手太阴之金从令而化湿。手阳明以燥金司化，足阳明之土从令而
化燥者常也。而手太阴之病燥，足阳明之病湿，是从化者自见其本气，以金性本燥，而土性本湿也。大抵足
太阳虽以寒化，而最易病热。手少阴虽以
热化，而最易病寒。厥阴原以风化，而风盛者固多。少阴虽以火化，而火败者非少。金性本燥，而
手太阴从土化湿者常有七八。土性本湿，而足阳明从金化燥者未必二三也。
There are twelve meridians, six of which govern Qi transformation (Qi Hua), and six of which follow the transformation (Cong Hua). The meridians that follow transformation do not independently govern Qi transformation; rather, they are entirely subordinate to those that govern it. Thus, the twelve meridians are unified under the Six Qi (Wind, Cold, Summer-heat, Dampness, Dryness, Fire). In disease, one may observe either the intrinsic Qi (Ben Qi) of the governing meridian or the intrinsic Qi of the following meridian; alternatively, the governing meridian may exhibit the Qi of the following meridian, or the following meridian may exhibit the Qi of the governing meridian. This depends entirely on the decline or prosperity of the intrinsic Qi.
The Hand-Shaoyin Heart Meridian is governed by Ministerial Fire (Jun Huo). It is common for the Foot-Shaoyin Kidney Meridian's Water to transform into Heat in accordance with the command. However, when the Foot-Shaoyin Kidney Meridian presents with Cold, this is the follower manifesting its own intrinsic nature, as Water inherently possesses Cold. When the Hand-Shaoyin Heart Meridian presents with Cold, this is the governor manifesting the Qi of the follower, as Ministerial Fire originally transforms from Water.
The Foot-Taiyang Bladder Meridian is governed by Cold Water. It is common for the Hand-Taiyang Small Intestine Meridian's Fire to transform into Cold in accordance with the command. However, when the Hand-Taiyang Small Intestine Meridian presents with Heat, this is the follower manifesting its own intrinsic nature, as Fire inherently possesses Heat. When the Foot-Taiyang Bladder Meridian presents with Heat, this is the governor manifesting the Qi of the follower, as Cold Water originally transforms from Fire.
The Foot-Jueyin Liver Meridian is governed by Wind-Wood. The Hand-Jueyin Pericardium Meridian's Fire transforms into Wind in accordance with the command. The Hand-Shaoyang Sanjiao Meridian is governed by Ministerial Fire (Xiang Huo). It is common for the Foot-Shaoyang Gallbladder Meridian's Wood to transform into Summer-heat in accordance with the command. However, when the Hand-Jueyin Pericardium Meridian presents with Summer-heat, and the Foot-Shaoyang Gallbladder Meridian presents with Wind, this is the followers manifesting their own intrinsic natures, as Fire generates Summer-heat and Wood generates Wind.
The Foot-Taiyin Spleen Meridian is governed by Damp-Earth. The Hand-Taiyin Lung Meridian's Metal transforms into Dampness in accordance with the command. The Hand-Yangming Large Intestine Meridian is governed by Dry-Metal. It is common for the Foot-Yangming Stomach Meridian's Earth to transform into Dryness in accordance with the command. However, when the Hand-Taiyin Lung Meridian presents with Dryness, and the Foot-Yangming Stomach Meridian presents with Dampness, this is the followers manifesting their own intrinsic natures, as Metal inherently possesses Dryness and Earth inherently possesses Dampness.
Generally speaking, although the Foot-Taiyang Bladder Meridian transforms via Cold, it is most prone to Heat diseases. Although the Hand-Shaoyin Heart Meridian transforms via Heat, it is most prone to Cold diseases. Jueyin originally transforms via Wind, so cases of excessive Wind are indeed numerous. Although Shaoyin transforms via Fire, cases of Fire failure are not few. Metal inherently possesses Dryness, yet the Hand-Taiyin Lung Meridian transforming into Dampness by following Earth occurs in seven or eight out of ten cases. Earth inherently possesses Dampness, yet the Foot-Yangming Stomach Meridian transforming into Dryness by following Metal occurs in only two or three out of ten cases.