Purvokta bijalohanametasyameve varnitam I
Uttamadhamamadhyapabhramsanam galanavidhau I
Musassaptottaracatussatabheda itiritah II
Meaning: In the melting methodology course, the good, the average, pig metals and 407 varieties of
Tasam dvadasavargah syurjatinirnayah kramat I
Meaning: In the order of origin there are 12 groups in them
Lohesu ye bijalohastesam galanakarmani II
Dvitiyavargoktamusa eva srestha itiritah I
Meaning: In the melting of base metals, it is said that the secondary group of crucibles are the best.
Etesaham galane musaha pratyekam vargatassmrtah I
Tesu dvitiyavargasthamysabheda maharsibhih II
Catvarimsaditi prokta musakalpa yathakramam I
Tasu ya pancamityukta musantrmukhanamika II
Galane bijalohanam suprsasta itiritah II
Meaning: In the melting of these base metals, crucibles are remembered from each class of these. The Crucible varieties in the second category are mentioned as forty, in order, by the great sages, in their work for Musha kalpa.
Crucible is a container that can withhold high temperature. It is used for the process of melting metals and alloys. The steel was produced by heating wrought iron with materials rich in carbon, such as charcoal, in a closed vessel. It was described in Indian civilization and other civilizations of Greece, Syria, and Persia. Historically, they were usually made from clay. The crucible process was later rediscovered by the British in 1740.
But according to the ancient records, it has been noted that, first supply of weapons to people of Mediterranean came from India in the form of Wootz steel. This specific steel was used in the making of Damascus blades.
This steel metal was widely available in the southern part of India. The name ‘wootz’ was derived from the Kannada word ‘Ukku’ which means ‘steel’. Ancient literature suggests that the Southern part of India exported steel to China, Europe and Middle East countries.
Bharadwaja Rishi in his “Brihad vimana Sastra” has stated the art of making crucibles. So it can fairly be told that Crucibles have its origin in ancient India.
“Nirnayaadhikaara” states that different kinds of crucibles are used for melting different metals. There were about 407 varities of crucibles. To choose the right crucible for right metal, the ancient metallurgists divided metals into 12 groups. And the 12 kinds of metals are:-
- Kritaka or artificial
- Apabhramshaka or corrupted
- Sthalaja or mud born
- Khaniji or found in mines
- Jalaja or aquatic
- Dhaatuja or mineral born
- Oshadhivargaja or Vegetarian-born
- Krimiji or evolved from vermin
- Maamsaja or flesh born
- Kshaaraja or grown from salts
- Baalaja or hair born
- Andaja or resultant from egg
The art of making crucibles was known as “Mooshakalpa”.
The ingredients used by ancient Indians to make crucibles were- Black gram flour, metal, metal rust, laanglee or jussieuea repens, ruruka, gum arabic, salt-petre, 5 types of grass, creepers, paddy husk ash, naagakesera, arsenic, borax, scented grass, Sindoor and sea foam. Proportionate mixture of all these ingredients are grounded and made fine powder. To this powder, equal quantity of gum is added along with dust and earth parts. This mixture is then baked for 9 hours in a vessel with shivaaree oil.
After baking, all the contents are then poured into a crucible mould. The final product is the ‘Crucible’.
In the current day, crucible is a cup-shaped piece of laboratory equipment used to heat compounds at high temperature. Crucibles are available in different shapes and sizes. Crucible are generally made up of high heat-resistant materials like alumina, porcelain, inert metal. Recently, metals like nickel, zirconium have also been used.