Bàn ngoại đan, trọng tâm tính chất chì–thủy ngân và lý luận luyện đại đan. Được mục lục Tống đại ghi nhận; là văn bản ngắn về huyền lý và thực tiễn lô hỏa.
Ứng dụng: Nghiên cứu lý luận chì–thủy ngân và hỏa hầu ngoại đan.
唐宋外丹短論，洞神部眾術類。核心命題：龍者汞、虎者銀（真鉛）；「汞於砂中而受氣，銀於鉛中而受氣，二氣各得天地之元氣」。金性冷、產南方水中（汞生於砂）為「陽中有陰」離位；石性熱、產北方為坎位。主張以銀為真鉛、砂汞為龍虎交媾之基，反對專執凡砂凡鉛。與唐代「煉銀於鉛，神功自然，灰池炎爍，鉛沉銀浮」歌訣同系，為鉛汞派大丹理論的精煉表述，常被引以證「真鉛真汞」非市井之物。
⚡ Ứng dụng: 外丹立論時釐清真鉛真汞：取砂中汞、鉛中銀為龍虎，配合卦氣火候煉大丹；亦可作內丹坎離鉛汞的外象參照。
🔗 Liên quan: 大丹鉛汞論；周易參同契；龍虎還丹訣
Da Dan Ji proves that the Great Elixir is a staged transformational sequence with observable phase-signs; success is recognized by correct transitions, not by duration alone. The record functions as a causal log: ingredients, fire, times, and endpoints form a reproducible argument.
1) Translate the text’s stages into a checklist for neidan (or historical study for waidan): essence stabilization → qi movement → spirit condensation → resting. 2) Pair stages with BaZi periods: do not force late stages in years of severe Resource drain. 3) Define failure signs (agitation, insomnia, compulsive heat) as phase errors, not ‘tests from demons’ only. 4) Time stage shifts to monthly gua or solar terms per companion alchemical calendars. 5) Write your own 記 after each retreat—make personal causality as explicit as the classic.
Unlike 神仙養生祕術 (plural techniques for nurturing life) or 靈草歌 (herbal songs), Da Dan Ji centers one grand process model. It differs from purely philosophical 悟真篇 poetry by presenting record-like procedural logic; the why is to prove reproducibility of the ‘great’ work through staged evidence.