1. यन्त्र (Yantra) – निरुक्ति (Etymology)

The Sanskrit word यन्त्र (Yantra) is derived from the root verb “यम्” (yam), which means to control, to restrain, to bind, or to support. The suffix “त्र” (tra) is used to form words that denote an instrument or a tool.

Therefore, the निरुक्ति (etymological meaning) of यन्त्र is “an instrument or mechanism that controls, restrains, or holds something.” In the context of Rasashastra, a yantra is any apparatus or contrivance used to perform a specific alchemical or chemical operation, such as distillation, sublimation, or heating.

2. मूषा (Mūṣā) – आधुनिक स्वरूप (Modern Form)

मूषा (Mūṣā) is a crucible, a cup-shaped container made of clay or metal used for heating substances to very high temperatures.

• आधुनिक स्वरूप (Modern Form): The modern equivalent of a Mūṣā is a laboratory crucible, typically made of materials like:
  • Porcelain (for general use)
  • Platinum (for high-temperature, reactive substances)
  • Nickel (for alkali fusions)
  • Graphite or refractory clay

Categories of Yantras (Apparatuses)

The following terms are specific types of yantras used in alchemical processes.

Heating and Roasting Apparatuses:

• दोलायन्त्र (Dolāyantra): A swinging or suspended apparatus, often used for continuous and gentle heating. It resembles a sand bath or a water bath where the vessel is suspended and swung over a heat source.
• डमरुयन्त्र (Ḍamaru Yantra): Named after the hourglass-shaped damaru drum. It is used for sublimation processes where two vessels are joined together, forming a closed chamber.
• पालिकायन्त्र (Pālikāyantra): A vessel used for the purification of materials like sulfur (gandhaka) by a melting and cooling process. Similar to a melting pot.
• स्थालीयन्त्र (Sthālīyantra): Essentially a water bath or steam bath. It consists of an outer vessel containing water and an inner vessel containing the material to be heated gently.
• स्वेदनीयन्त्र (Svedanīy Yantra): An apparatus specifically designed for steam distillation or sweating of herbs/minerals. A precursor to the modern steam distillation setup.
• बालुकायन्त्र (Bālukāyantra): A sand bath. A pot filled with sand is heated, and the crucible containing the material is placed inside the hot sand to ensure uniform and controlled heating.
• चुल्लिका (Cullikā): A simple, small, open furnace or hearth used for heating crucibles (mūṣā).
• अङ्गारकोष्ठिका (Aṅgārakoṣṭhikā): A closed furnace or an oven heated with charcoal. It provides a enclosed, high-temperature environment.

Sublimation Apparatuses:

• कोष्ठी (Koṣṭhī): A general term for a closed apparatus, but often refers to a specific type of sublimation furnace made of brick and clay. It is a complex structure with multiple chambers for controlled heating and cooling.
• पातालकोष्ठिका (Pātālakoṣṭhikā): A type of sublimation apparatus where the sublimed material is collected in the lower chamber. (Pātāla means the lower regions).
• गारकोष्ठी (Gārakoṣṭhī): Another type of sublimation apparatus, similar to Koṣṭhī.
• विद्याधरयन्त्र (Vidyādhar Yantra): Literally “the celestial being’s apparatus,” this is a sophisticated sublimation apparatus designed for efficient collection of sublimed material. It often has a design that allows for cooling of the upper chamber.

Distillation Apparatuses:

• पातनायन्त्र (ऊर्ध्व) (Pātanāyantra – Ūrdhva): An upward distillation or ascending distillation apparatus. The distillate vapors rise and are condensed and collected in an upper chamber. Used for substances lighter than water.
• अधःपातनयन्त्र (Adhaḥpātan Yantra): A downward distillation or descending distillation apparatus. The distillate vapors are condensed and trickle down into a lower collection vessel. This is the classical design for an alembic and is used for distilling substances heavier than water (e.g., mercury, oils).

मूषा (Crucible) Related Terms

• मूषा के सन्धिबन्धनार्थ द्रव्य (Mūṣā ke sandhi-bandhanārtha dravya): These are the substances used for sealing the joints of the crucible to make it airtight. This was crucial to prevent the escape of vapors and to control the atmosphere inside. Common materials included:
  • Multani Mitti (Fuller’s Earth)
  • Lime paste
  • Cloth smeared with wet clay
  • Wheat dough
• मूषाबन्धन के पर्याय (Mūṣābandhan ke paryāya): Synonyms or alternative terms for the process of sealing the crucible. Examples include Sandhi Lepa (applying paste to the joints), Mūṣā Saṃyojana (joining the crucible), etc.

मुद्रा (Mudrā) – Seal or Gesture

• मदन मुद्रा (Madana Mudrā): A specific type of seal or closure used for apparatuses. The name suggests it was considered very effective or “intoxicatingly good” (madana) at preventing the loss of energy or matter.
• हठमुद्रा (Haṭha Mudrā): A forceful or strong seal, implying an airtight, unyielding closure achieved perhaps with multiple layers of sealing material, ensuring no vapors could escape during intense heating.

Summary Table