脐下有丹田，有活见之处，而不可以分寸计。人之动气，根于两肾，生于丹田。气足内藏，鼻息微细；气
虚上奔，鼻息喘促。无气有气，有气无气，以此为辨。而名为丹田者，则非医家所能通晓。余与梯云道人（姓
谢，字际洛，新化人。甫八岁，病狂，所言皆蓬莱海岛之事，十四岁方瘳。十五岁发蒙，越明年，游泮。一动一
静，无不以圣贤自规）。了悟山人（姓刘，讳宗因，字群占，号济南，邵阳人。天生一种慈详恺恻之性，日以
普渡众生为念。鬓发雪白，满面红光。梦觉道人游湘，寄书未至，预对家人白之。有“可知息息相通处，未见
瑶函先见形”之句），同考道于梅城雷公洞（在城南九十里，洞窈而深，巨石摩霄，塞口一水冲破。梦觉道人
循口壁凿开，为新邵通衢，约一里许。正居洞中间，傍溪献一大岩，生成考道之所。基砥而垲爽，顶锅而风藏。
门面奇花异草，四时 HT 。壁脚方床圆几，百窍玲
珑。不寒不暑，常在二八月天气；有炉有灶，包含亿万劫金光）。忽一朝，谢子微笑曰∶“吾今知脐下为丹
田，乃藏丹之所也。昨宵漏永，宝鼎浓浓。光透帘帏，夺得金精一点。恍兮惚兮，活见于脐下矣。”余曰∶“
水中之铅，经火一炼，化而为丹。些子机关，只可自知，余亦将有得，不堪持赠君尔。”时刘子犹未悟也。谢子
灵根夙植，仙骨珊珊，雅有逸鹤闲鸥之致，闻道独早，三人参究原理，得益于谢者居多，厥后刘亦勇于上进。
一痕晓月东方露（坎戊，月精。晓月露者，药苗生也），穷取生身未有时（天地未有时，先有贞元会合之真气，
而后有天地；生身未有时，先有贞元会合之真气，而后有生身。晓月露，追取先有之真气，归于生身）。其
所得更有过于余与谢者。桃花夙有约，同泛武陵槎（陶渊明《桃花源记》∶武陵人，捕鱼为业。缘溪而行，忘
路之远近。忽逢桃花夹岸，数百步中无杂树，行到源头，山有小口，仿佛若有光。舍船从口入，其中往来种作，
男女衣裳，悉如外人，黄发垂髫，怡然自乐。自云先世避秦人乱，来此绝境，不复出焉，遂与外人间隔）。
肚脐下方有丹田，这是生命活动显现的关键部位，不能用具体的尺寸来衡量。人的元气，根源在于两肾，生成于丹田。如果气充足且内藏，鼻息就会微弱细微；如果气虚弱而上冲，鼻息就会气喘急促。通过观察“无气”与“有气”、“有气”与“无气”的状态变化，以此作为辨别依据。至于“丹田”这一名称的真正含义，则不是普通医生所能透彻理解的。
我与梯云道人（姓谢，字际洛，新化人。刚八岁时，患狂病，所说的话都是关于蓬莱海岛的事情，直到十四岁才痊愈。十五岁开始启蒙读书，第二年便考中秀才。一举一动，无不以圣贤的标准来规范自己）和了悟山人（姓刘，名宗因，字群占，号济南，邵阳人。天生一种慈祥恺恻的性格，每天以普渡众生为念。鬓发雪白，满面红光。梦觉道人游历湖南时，寄信未到，他预先对家人说：“可知息息相通之处，未见书信先见身影。”的诗句）一起，在梅城雷公洞考察修道之法（位于城南九十里处，洞穴幽深，巨石高耸入云，洞口有一水流冲破。梦觉道人沿着洞口壁面凿开，开辟为新邵的通途，约一里多长。正居于洞中间，旁边溪流旁有一块大岩石，天然形成考道之所。地基平坦干燥清爽，顶部如锅状而风被隐藏。门面奇花异草，四季盛开。壁脚方床圆几，百窍玲珑剔透。不冷不热，常保持在二八月般的宜人天气；有炉有灶，包含亿万劫的金光）。
忽然有一天，谢子微笑着说：“我现在知道脐下为丹田，是藏丹的地方。昨夜漏刻漫长，宝鼎中的精气浓郁。光芒透射帘帏，夺得了一点金精。恍惚之间，活现的生机出现在脐下。”我说：“水中的铅，经过火的一番炼制，化为金丹。这其中的关键机关，只可自知，我也将有心得，但不堪拿来赠送给你。”当时刘子还未能领悟。谢子灵根素来植就，仙骨珊珊，颇有逸鹤闲鸥的情致，闻道独早，三人参究原理，得益于谢子的居多，后来刘子也勇于上进。
“一痕晓月东方露”（坎戊，月精。晓月露者，药苗生也），穷取生身未有时（天地未有时，先有贞元会合之真气，而后有天地；生身未有时，先有贞元会合之真气，而后有生身。晓月露，追取先有之真气，归于生身）。他所获得的境界更有超过我和谢子的。桃花夙有约，同泛武陵槎（陶渊明《桃花源记》：武陵人，捕鱼为业。缘溪而行，忘路之远近。忽逢桃花夹岸，数百步中无杂树，行到源头，山有小口，仿佛若有光。舍船从口入，其中往来种作，男女衣裳，悉如外人，黄发垂髫，怡然自乐。自云先世避秦人乱，来此绝境，不复出焉，遂与外人间隔）。
Below the umbilicus lies the Dantian (Elixir Field), a place where vital life manifests, which cannot be measured by standard units. Human Yuan Qi (Primal Qi) originates in the two Kidneys and is generated in the Dantian. When Qi is sufficient and stored internally, nasal breathing is faint and fine; when Qi is deficient and rushes upward, nasal breathing becomes panting and rapid. The distinction between "having no Qi" and "having Qi," or "having Qi" and "losing Qi," serves as the criterion for differentiation. However, the true meaning of the term "Dantian" is not something that ordinary physicians can fully comprehend.
I, along with Tiyun Daoren (Master Cloud Ladder, surname Xie, courtesy name Jiluo, from Xinhua. At eight years old, he suffered from mania, speaking only of events on Penglai Island, until he recovered at fourteen. He began his education at fifteen, and the following year passed the county examination. In all movements and stillness, he regulated himself according to the standards of sages) and Lewu Shanren (Hermit Awakened to Truth, surname Liu, given name Zongyin, courtesy name Qunzhan, pseudonym Jinan, from Shaoyang. Born with a naturally kind, compassionate, and gentle nature, he devoted each day to the universal salvation of sentient beings. His hair and beard were snow-white, yet his face glowed with rosy health. When Mengjue Daoren traveled through Hunan and sent a letter that had not yet arrived, Liu predicted to his family: 'It is known that where breaths connect, before seeing the jade letter, one sees the form.'), studied the Dao together at Leigong Cave in Meicheng (located ninety li south of the city, the cave is profound and deep, with massive rocks brushing the sky, and a stream breaks through the entrance. Mengjue Daoren chiseled open the cave wall to create a thoroughfare for Xinshao, approximately one li long. Situated in the middle of the cave, beside the stream stands a large rock, naturally formed as a place for studying the Dao. The foundation is flat and dry, the roof pot-shaped sheltering the wind. The facade features exotic flowers and herbs blooming in all seasons. Square tables and round stools by the wall are intricately carved. Neither cold nor hot, it maintains the pleasant weather of the second and eighth lunar months; with stoves and furnaces, it contains the golden light of countless kalpas).
Suddenly, one morning, Master Xie smiled and said, "I now understand that below the umbilicus is the Dantian, the repository of the Elixir. Last night, as the water clock dripped slowly, the essence in the Precious Cauldron was dense. Light penetrated the curtains, capturing a single point of Golden Essence. In a state of恍惚 (huanghu - vague and indistinct), the living manifestation appeared below the umbilicus." I replied, "The Lead from Water, once refined by Fire, transforms into the Elixir. This subtle mechanism can only be known by oneself. I also have my own insights, but they are not suitable for gifting to you." At that time, Master Liu had not yet attained enlightenment. Master Xie possessed innate spiritual roots and ethereal bones, exhibiting the demeanor of an idle crane and free gull. He encountered the Dao early. The three of us investigated the fundamental principles, benefiting mostly from Master Xie, after which Master Liu also became diligent in advancing.
"A trace of dawn moon emerges in the eastern dew" (Kan Wu, essence of the moon. Dawn moon dew signifies the sprouting of medicinal herbs), "Exhaustively seeking what existed before birth" (Before heaven and earth existed, there was first the True Qi of the union of Zhen and Yuan; then heaven and earth came to be. Before physical birth, there was first the True Qi of the union of Zhen and Yuan; then physical birth occurred. Dawn moon dew refers to pursuing this primordial True Qi and returning it to the source of life). His attainment surpassed that of myself and Master Xie. "A prior appointment with peach blossoms, together we float on the raft of Wuling" (Tao Yuanming's *Peach Blossom Spring*: A fisherman from Wuling made his living fishing. Following a stream, he forgot the distance. Suddenly, he encountered peach trees lining the banks for hundreds of steps, with no other trees mixed in. Reaching the source, there was a small opening in the mountain, seemingly emitting light. Leaving his boat, he entered through the opening. Inside, people came and went farming. Men and women dressed like outsiders, the elderly and children were happy and content. They claimed their ancestors fled the chaos of the Qin dynasty and came to this isolated place, never leaving, thus becoming separated from the outside world).