Huangzhong at Sixty Fen and Ruibin at Fifty-Three: How Does the Mirror Classic Detect Deviation from Pulse-Law Baselines?

“Qiheng” first reconfirms the baseline established near the beginning of the work:

When one complete breath contains five pulse movements and qi travels sixty fen, like a drawn cord of equal size, upper and lower corresponding, going together and coming together, this is called the normal person.

It also names this vessel-route measure Huangzhong.

Yet the same chapter soon gives another set of numbers:

In one exhalation pulse movement begins at Cheng, and the next movement reaches Shi and likewise rises; entering Jin, qi travels two Cun seven fen. In one inhalation pulse movement begins at Qin and likewise enters Jin; qi travels two Cun six fen. Together, in one breath qi travels five Cun three fen; the lü follows Ruibin, the lü of the right Foot Taiyang.

This is extremely important because it shows that “sixty fen” is not the only possible pulse-lü scale.

Huangzhong is a baseline, not a demand that every channel equal sixty fen

Huangzhong at sixty fen establishes the normal vessel-route constant. But the Twelve Lü are themselves a system of different divisions, so other channels can have different qi-movement scales according to their lü.

Here, one breath of right Foot Taiyang travels five Cun three fen and is assigned to Ruibin.

Normality and abnormality therefore cannot be judged only by asking “is it six Cun?” One must also ask: which channel is currently being examined, which lü should govern it, and do its starting and ending Hou positions correspond?

Exhalation and inhalation may even be asymmetrical

In this example, exhalation measures two Cun seven fen and inhalation two Cun six fen, together totaling five Cun three fen.

This suggests that the Mirror Classic permits different divisions for the two respiratory phases rather than forcing one breath into two exactly equal halves.

Deviation is judged by “proper position / lost position,” not by numerical size alone

The text immediately goes on to discuss increase and decrease of true qi, what overcomes and what cannot be overcome, following and counterflow, and pathogenic qi. It says that qi “arises when it reaches its proper position” and “becomes severe when it reaches what it cannot overcome.”

The same numerical change may therefore mean different things depending on whether it occurs at the expected position and phase. True abnormality is a mismatch among value, position, and relation.

Qiheng here completes a normal-to-deviation framework

Qiheng does not primarily list disease names. Its sequence is:

establish the constant → identify the governing lü and Hou → observe waveform and travel path → then judge increase/decrease, following/counterflow, and proper/lost position.

The next series, “Kuidu,” organizes these observations into a more explicit inferential procedure.