狐丘，亦称狐刚子，是一位在东汉末年活跃的炼丹高手，其生卒年份和籍贯均未有详细记载。据陈国符先生考证，狐刚子可能与葛洪同时生活，他的著作《五金诀》中，将他誉为“最大之外丹黄白师”。赵匡华先生则认为狐刚子的真名是丘，又被称为胡罡子或狐罡子。他是一位杰出的化学家和炼丹术士，对于黄白术有着深入的研究，并留下了一些重要佚文。

他的著作包括《五金粉图诀》、《出金矿图录》、《河车经》、《玄珠经》，以及可能遗失的一部《金石还丹术》。在这些作品中，狐刚子不仅阐述了炼制黄金和白银的方法，还探讨了金属的地质分布、采集技巧，以及冶炼工艺等方面。此外，他对水银提炼法进行了改进，使得水银提炼率大幅提高，为后世奠定了基础。

foxes' secret recipe: fox chui, also known as fox gongzi. alchemist. historical records unknown. his birth and death dates are not clear. according to mr. chen guofu's research, fox gongzi may have lived around the same time as ge hong, and he wrote "wujin jue" in which he referred to fox gongzi as "the greatest external elixir yellow-white master". mr. zhao kuanghua believes that fox gongzi's real name was qiu, also known as hu gangzi or fu gangzi.

as an outstanding representative of eastern han dynasty alchemy, fox gongzi made significant contributions to the field of metallurgy and chemistry. his works include "wujin fen tu jue", "chukou jingluo", "hechei jing", and possibly a lost work titled "jinshi huan dandanshu". although these writings are scattered throughout history, they demonstrate the advanced level of metallurgical science during that period.

fox gongzi was particularly skilled in gold and silver refining techniques. he introduced new methods for extracting mercury from cinnabar (dan shan), including a closed-vessel distillation method that revolutionized mercury extraction in china at the time.

his other notable achievements include developing a nine-stage lead oxide refining process (jiuzhuan qindan fa) for producing lead(II) oxide (pb3o4), one of the earliest recorded processes for this purpose in chinese literature.

overall, despite limited information about his life and works surviving through history, fox chui has left behind an invaluable legacy in ancient chinese metallurgical science that continues to inspire researchers today.

foxes' secret recipe: fox chiu (), also called chiu kung-tzu (). alchemist who flourished during late eastern han dynasty () with unclear birthdate & residence place; regarded by some historians like Mr Chen Kuo-fu () as contemporaneous with Ge Hong () - author of 'Wujin Jue' where Fox Chi'u is hailed as 'the Greatest External Elixir Yellow-White Master'. Zhao Kuang-hua (), another historian claims Fox Chi'u had three names - Chiu (), Hu Gang-chi or Fu Gang-chi.

As an influential figure among Eastern Han Dynasty Alchemists(), Fox Chi'u contributed significantly to Metallurgy & Chemistry(). His published works include:

1.) Five Gold Powder Diagram Secret Methodology

2.) Extracting Mineral Deposits Record

3.) River Carriage Chronicle

4.) Celestial Jade Scripture

In addition there might be another lost manuscript called Golden Stone Returning Elixir Technique(). Although most original texts have been dispersed over time; still it can be inferred from remaining fragments how much knowledge on Metalogical Science reached its peak during those days.

Fox Chi'u excelled especially when handling gold & silver processing methods.

He invented innovative ways for obtaining Mercury from Cinnabar(Dan Shan): Closed-Vessel Distillation Method

which greatly improved Mercury production efficiency within China at that moment

His accomplishments extend beyond just refining techniques:

Developed 9-step Lead Oxide Refining Process("Jiuzhuan Qindan Fa")to create PbO3

a technique considered one amongst first ever documented instances concerning this subject matter within Chinese Literature

In summary despite having very little available information about him surviving till our times; what remains offers insight into Ancient Chinese Metallurgical Science continuingly inspiring modern-day researchers