Burnt Yellow Earth, Zao Xin Tu 灶心土

Old Oven Earth, Burnt Earth, Terra Flava Usta
Khazaf: Oven Clay, Clay pottery (Unani)
Zao Xin Tu (TCM)

Clay Oven (Tabun)
Arbeit und Sitte in Palästina (Gustaf Dalman, 1935) (Wikimedia)

Minerological name:
Terra flava usta (Burnt Yellow Earth)

Parts used:

Traditionally, the old burnt Earth used in the construction of stoves was used in China, this being collected when an old stove was destroyed or repaired. Generally today, burnt Yellow Earth is used in its place.
In the West, Oven clay, Pipe clay and sometimes old bricks were used similarly, being fired or burnt earth and therefore warmer and dryer than regular clay-Earth.

Temperature & Taste:

Warm, dry. Pungent
“The dirt of furnace is warming in the last phase of the second degree” (Avicenna)

Classification:

L. Stop Bleeding

Uses:

1. Warms the Blood, Stops Bleeding:
-Cold-type Bleeding, especially when associated with deficiency (weakness)
-especially for Bleeding from the Stomach, or Blood in the Stool
-continuous Uterine Bleeding, Excess Menstruation
-also to Calm the Fetus during pregnancy

2. Warms the Stomach, Stops Vomiting:
-vomiting from Coldness of the Stomach
-Morning Sickness

3. Clears Cold, Stops Diarrhea:
-Chronic Diarrhea from Spleen/Digestive weakness
-“Furnace dirt is moderately detergent and highly absorbent” (Avicenna)

4. Externally:
-Swollen Sores, mix with Garlic juice and apply, changing regularly
-Blisters from burns, decoct and use the water as a wash
–Avicenna said Clay Earth was useful for Ulcers when used topically
-“Furnace dirt is highly detergent for ringworm” (Avicenna)
-painted onto Gout/Arthritis (Avicenna)
–Pterygium, Oven Clay is mixed with Rock Salt and used topically (Avicenna)

Dose:

Decoction: 10–30 grams (placed into a cheesecloth bag and decocted 15–30 minutes before adding other herbs.

Comment:

This is another one of the Earth medicines, this differing in being warmer and more dry, and therefore best for cases with Cold and Deficiency. Several types of this medicine can be found in traditional texts. Other types of fired clay such as bricks have also been used similarly.

Substitute:

Avicenna said Brick clay resembled the properties of Hematite

Main Combinations:

1. Bleeding:
i. from Spleen deficiency (where Spleen can’t control the Blood), Burnt Yellow Earth with Bu Zhong Yi Qi Tang.
ii. from Qi deficiency, Burnt Yellow Earth with Notoginseng San Qi, Astragalus Huang Qi, Codonopsis Dang Shen
iii. from Cold, Burnt Yellow Earth with Blast-fried Ginger (Pao Jiang), carbonised Mugwort (Ai Ye), Schizonepeta Jing Jie
iv. Cold and deficient, Burnt Yellow Earth with Astragalus Huang Qi, Mugwort (Ai Ye), Ginger (Pao Jiang)
2. Chronic Blood in the Stool from deficiency, Burnt Yellow Earth with Cinnamon, Dang Gui, Mugwort leaf (Ai Ye)
3. Vomiting from Stomach weakness, Burnt Yellow Earth with Atractylodes Bai Zhu, Amomum Sha Ren
4. Morning Sickness, Burnt Yellow Earth with fresh Ginger
5. Chronic Diarrhea:
i. from Spleen weakness with Cold, Burnt Yellow Earth with Atractylodes Bai Zhu, Ginger, Licorice
ii. Burnt Yellow Earth with Red Earth (Chi Shi Zhi)

Major Formulas:

Huang Tu Tang

Cautions:

1. Avoid in Bleeding due to Yin deficiency.
2. Not for Vomiting from Stomach Heat
3. The oven earth used should not have been used for burning coal.