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Minerals and Metals in Ancient India v2.c45.s7: Rasa and Rasaka in RRS

Minerals and Metals in Ancient India v2.c45.s7

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Rasa and Rasaka in RRS

v2.c45.s7.1

Mercury was reckoned as a very important metallic element in Indian alchemy and believed to be able to ‘transmute’ base metals to gold, and to provide an ‘elixir of life’. It was known as: *raso rasendraḥ sutaśca pārado miśrakastathā ‘rasa, rasendra, suta, pārada and miśraka’* (1.68). *Rasa* is that *rasanāt sarvadhātunām rasa iti abhidhīyate* which consumes all metals into liquid’ or amalgamates (1.77). *Pārada* ‘takes the persons across the oceans of diseases’.

v2.c45.s7.2

Mercury was obtained by distillation of cinnabar or *hingula/darada* in a *Vidyādhara Yantra* (9.57). The distillate was called *hingulākṛṣṭa rasa* (8.37). Cinnabar was known to occur in two varieties: low quality *śukaṭuṇḍa* or *carmāra* and good quality *haṃsapāda*, having white lines and looking like coral (3.141-144).

v2.c45.s7.3

Yaśodhara had quoted Nāgārjuna in his *Rasaprakāśasudhākara*: *pārado rasakaścaiva dehalohakarāvubhau* that both *rasa* or *pārada* (mercury) and *rasaka* (zinc ore/metal) when administered, make the body strong. Both the metals are distillation products, and hence the similarity in the names: *rasa* and *rasaka*.

v2.c45.s7.4

RRS stated that rasaka or calamine occurred in two forms: durdura, full of flakes or laminated, and kāravellaka, which is non-laminated (2.149). Other Rasaśāstra texts have provided other synonyms for rasaka such as kharpara, netrarogāri(zinc salt might have been used in eye-ointments), rītikṛt, tāmrarañjaka, etc. Mṛttikā type ore is yellow, rich in metal, not losing weight when heated. Guḍa and pāṣāṇa varieties are of inferior quality.

v2.c45.s7.5

Calamine was supposed to be purified by roasting and plunging in acidic lemon juice, urine, or sour gruel (2.154-155). Zinc ore of Rajasthan occurs in calcitic and dolomitic gangue. Probably the operation recommended in RRS removed carbonates by thermal decomposition and acidic dissolution. Smelting involved reduction-roasting of zinc ore with carbonaceous materials and borax in brinjal-shaped crucible or vṛntāka mūṣā:

v2.c45.s7.6

वृन्ताक आकार मूषायां नालं द्वादशांगुलम्
धत्तुरपुष्पवत् च उर्ध्वं सुदृढं श्लिष्टपुष्पवत्।
अष्टांगुलं च सच्छिद्रं सा स्यात् वृन्ताक मूषिको
अनया खर्परादीनां मृदुनां सत्वमाहरेत्।।
vṛntāka ākāra mūṣāyāṃ nālaṃ dvādaśāṅgulam
dhattura puṣpavat ca urdhvaṃ sudrḍhaṃ śliṣṭapuṣpavat ।
aṣṭāṅgulaṃ ca sacchidraṃ sā syāt vṛntāka mūṣiko
anayā kharparādīnāṃ mṛdunāṃ satvamāharet ।।
(RRS, 10.22-23)

v2.c45.s7.7

Vṛntāka mūṣā or brinjal-shaped crucible is attached with a twelve-angula long tube over it like an inverted flower of dhattūra. A hole is made at the length of eight angula in the tube. This crucible is used for the extraction of satva (metal zinc) from the soft drugs like kharpara, etc.

v2.c45.s7.8

Several techniques of smelting were discussed. According to the first method, the dried charge was to be heated in the crucible, closed and stacked one over another (mūṣām mūṣopari nyasya) and the reduction was supposed to be complete as soon as the blue flame (due to carbon monoxide) turned white (jvāla bhaved nilā sitā yadi), when the crucible was to be gripped by a pair of tongs and tilted to pour the molten metal (2.157-161). The second method involved mixing the charge thoroughly with binders and putting this in the crucible as pellets (gutikākrti) (2.163-164). The third method involved disillation of the produced zinc metal in the inverted crucible (adhomukham mūṣā) and collection of the condensed vapour in a vessel filled with water kept in a hermetically sealed container below the crucible (patitam sthālikā nīre satvam) (2.165-166). This last method was commercially followed in India.

v2.c45.s7.9

RRS described several varieties of brass or *pittala*:

v2.c45.s7.10

अथ पित्तलम् रीतिका काकतुण्डी च द्विविधं पित्तलं भवेत्। सन्तप्ता कांजिके क्षिपता ताम्राभा रीतिका मता।। एवं या जायते कृष्णा काकतुण्डीति सा मता।। गुर्वी मृद्वी च पीताभा सारांगी ताड़नक्षमा। सुस्निग्धा मक्ष्णांगी च रीतिरेतादृशी शुभा।। पूतिगन्धा तथा लघ्वी रीतिर्नेष्टा रसादिषु।।

v2.c45.s7.11

*atha pittalam* *ritikā kākatuṇḍī ca dvidvidhaṃ pittalaṃ bhavet* | *santaptā kāñjike kṣiptā tāmrābhā ritikā matā* || *evaṃ yā jāyate kṛṣṇā kākatuṇḍīti sā matā* || *gurvī mṛdvī ca pītābhā sārāṅgī tāḍanakṣamā* || *susnigdhā masṛṇāṅgī ca ritiretādṛśī śubhā* || *pūtigandhā tathā laghvī ritirneṣṭā rasādiṣu* ||

v2.c45.s7.12

*Pittala* is of two kinds — *ritikā* and *kākatundī*. The former on being heated and plunged into sour gruel, turns copper-coloured; the latter one turns black by the above treatment (5.191-193).

v2.c45.s7.13

A good variety of *ritikā* or *rīti* was stated to be heavy, soft, yellow, resistant to hammering or malleable (*tāḍanakṣamā*), brilliant and smooth. An unsatisfactory variety is pale yellow, hard, rough with spots, not malleable, foul-smelling (high sulphur?) and not suitable for medicinal purposes (5.193-194).

v2.c45.s7.14

Presumably the ‘good variety of *ritikā* or *rīti*’ is alpha-brass which is known to withstand a remarkable degree of deformation by cold work without the slightest sign of fracture. The other variety of *ritikā*, which is not malleable, could be either high zinc (more than 30 per cent) beta-brass, having low ductility, or leaded brass.

v2.c45.s7.15

For making statues, 1-4 per cent lead is added in brass to help in fluidity during casting. But lead is almost insoluble in the liquid and solid brass phases, and thus a little excess of lead appears as black globules and elongated grains; this also causes the turnings to break up into small pieces. *Kākatundī* was probably leaded brass, the source of lead being the zinc ore itself. The *RRS* mentioned (8.18-19) that lead was often used to make *śulvanāga* or copper-lead alloy.

v2.c45.s7.16

Brass used to be killed for medicinal purposes by heating with sulphur, orpiment, etc. (2.167 and 5.201).

Linked texts (2)