狐丘，亦称狐刚子，炼丹高手。其生卒年月及籍贯不详，但据今人考证，约与葛洪同时期，为晋代人。狐刚子以“最大之外丹黄白师”著称，其《五金诀》对炼丹术有深远影响。他名丘，又作胡罡子、狐罡子，是东汉末年的一位杰出代表人物，与魏伯阳和葛玄齐名。
在他的著述中，我们可以窥见他在化学领域的卓越成就。他撰写了多部作品，如《五金粉图诀》（又称《粉图经》、《粉图》、《五金诀》，或《狐刚子万金诀》）、《出金矿图录》、《河车经》、《玄珠经》，以及可能的另一部作品《金石还丹术》（见于《通志·艺文略》）。这些著作反映了他对金属性状、地质分布、采集与冶炼工艺的深入研究。
fox-gang-zi, a renowned alchemist of the Eastern Han period. His exact birth and death dates are unknown, but based on modern research, it is believed that he lived around the same time as Ge Hong. Fox Gangzi was known for his expertise in yellow-white elixirs and was referred to as "the greatest outside dan yellow-white master." His work "Wujin jue" had a profound impact on alchemy.
Fox Gangzi's real name was Chiou, and he also went by Hu Ganzi or Fox Ganzi. He was an outstanding representative of the art of making yellow-white elixirs during the late Eastern Han period, with Wei Boyang possibly being his teacher and Ge Xuan possibly being his student.
His writings reflect the high level of alchemical knowledge achieved in China during that time. Unfortunately, much of his work has been lost over time, but some fragments have been preserved in early Tang dynasty works such as "Huangdi jiu ding shen danjing jue" and Tang dynasty treatises on white elixirs like "Longhu huandan jue" and "Tao gu tu duijing."
Fox Gangzi's contributions to chemistry were significant. He is credited with developing methods for extracting gold from mercury vapors using a process called blowing dust (making metal liquid) followed by washing with salt powder to obtain extremely fine gold particles. This method remained popular among later alchemists until at least the Ming dynasty.
In addition to these accomplishments, Fox Gangzi made important contributions to metallurgy and geology. For example, he developed an improved method for producing copper sulfate from azurite ore through calcination under controlled conditions.
Furthermore, Fox Gangzi demonstrated a keen understanding of chemical reactions involving metals like lead (Pb). His text describes techniques for preparing lead-based compounds used in medicine at that time.
Overall, while we know relatively little about this enigmatic figure named fox gang-jiu who flourished during one pivotal era in Chinese history when people sought immortality through internal practices like meditation or external means such as ingesting substances thought capable of prolonging life indefinitely - namely what we now call 'alchemy,' - it is clear that fox gang-jiu left behind lasting legacies within fields ranging from metallurgy & geology right up into basic sciences themselves!
