that to make the breath circulate is an easy thing; on the contrary, it requires a lengthy apprenticeship. "The internal breath... is naturally in the body, it is not a breath which you go outside to seek; (but) if you do not get the explanations of an enlightened master, (all efforts) will be nothing but useless toil, and you will never succeed." Common ordinary respiration plays only a secondary role in the mechanism of Breath circulation, which goes on outside it. The two breaths, internal and external, carry on their movements in perfect correspondence. When the external breath ascends during inhalation, the internal breath contained in the lower Cinnabar Field also rises; when the external breath descends, the internal breath descends too and returns again to the lower Cinnabar Field. Such is the simple mechanism which governs the circulation of Original Breath. (Maspero 1981: 468) This is done in two phases: "swallowing the breath" [yanqi 咽氣] and making it circulate. And if there is only a single way of absorbing the Breath, there are two distinct ways of making it circulate. One consists of leading it so as to guide it where one wishes it to go, to an afflicted area if it is to cure a malady, to the [niwan] if Embryonic Respiration is the purpose, and so on. This is what is called "guiding the breath" [xingqi]. The other consists of letting the breath go where it will through the body without interfering by guiding it. This is what is called "refining the breath" [lianqi]. I shall point out in succession the methods for absorbing the breath, for guiding it, and for refining it. It is the first of these two pulses. Absorbing the Breath, which is properly to be called Embryonic Respiration [taixi]: but the expression is applied also to the exercises in toto. (Maspero 1981: 469–470). Song dynasty Xingqi breath circulation continued developing during the Song (960-1279). Among the many progressive series of Daoist breath-circulating exercises ascribed to famous masters such as Chisongzi and Pengzu, one more complex set is attributed to the lesser-known Master Ning, the Ning xiansheng daoyin fa (寧先生導引法, Master Ning's Gymnastic Method). According to traditions, Master Ning was the Yellow Emperor's Director of Potters (taozheng 陶正). "He could gather up fire and not burn himself, and he went up and down with the smoke; his clothes never burned." (Maspero 1981: 543). His