8. Non-gem materials in the Varahamihira’s Brihatsamhita

We have earlier discussed the valuable references to gem minerals in Brihatsamhita, a composition belonging to the later part of the Gupta era (sixth century A.D.). This treatise also contains some useful references to rocks, non-gem materials and metals, which we propose to cite. The colour and plant associations of rocks enabled one to decide whether some rock had subsurface water. The rocks associated with munja or sacrificial grass, or a colour resembling beryl or green gram were likely to yield sweet water (BS.54.103 and 107). Lar coloured like the sun, fire or ashes (igneous rock) is likely to be waterless (BS 54.106) On the other hand: sasarkara nabhramahi kanayam saram dharitri krpila karoti apanduraya lavanam pravistam srstam payo nilavasundharaya a copper - coloured earth mixed with gravel or rocks with copper red spots (probably allude to garnet porphyroblasts) will yield

VIII-21 water with astringent taste; red-brown earth makes the water brackish; pale white earth salt water and blue earth, sweet water' (BS 54.104). Warahamihira prescribed several methods for quarrying massive rocks, using the principle of alternate heating and cooling for disintegrating the rocks (BS 54.112-114). Presence of horizonta and vertical joints some times helped in the quarrying of massive sand stones (like the Vindhyan sandstones) (Lahiri, 1971:496). Recently a series of stone quarries has been discovered near Chunar in Mirzapur. The Maurya period massive pillar-like stones were carefully chiselled. Maksika (pyrite) and silajatu (bitumen) powder were recommended (BS.76.3) as ingredients in health tonics. The use of alum as a mordant in the dyeing process were suggested: "tuvari (alum) manjistha (maddar dye) ragabandhani (colour binding). Earlier, Panini had suggested (4.1.42) the use of various dyes such as indigo, lac and red ochre; turmeric and maddar were mentioned in Samyutta Nikaya. Brhat Samhita described several preparations of cements or powders called vajra-lepa, characterised as 'paints or coatings as strong as Vajra or diamond'. The various recipes included. concentrated aqueous extracts of plant products rich in gummy and resinous substances, levigated powder of lac, resins, gummy fruits, concentrated extract of animal matters rich in glue or gelatine etc. (Bs.57.1-7).These were used as cements in temple architecture. The metal cement vajra - sanghata was described as: astau sisakramaga kamsasya ho ta ritikabhagah | jayakathito yogah ayam viseyo vajrasamghatah ||

VIII-22 'a compound of eight parts of lead, two of bell-metal, and one of brass has been mentioned by Maya and is to be known as Vajra-sanghata, a metal joining cement'. This was possibly used in hot soldering of broken metallic parts of the idol, made of bronze or brass etc. In a separate chapter (no.50) on swords, entitled khargalaksanam d Varahamihira provided some recipes about the hardening of steel which was called sastrapana or 'sword-drink' (the word sastra had been used in Yavanajataka to indicate steel) A sword rubbed with sesamum oil, and then smeared with an unguent prepare with the juice of the plant arka (calotropis gigantea), the gelatine from the horn of the sheep, and the excreta from the doves and mice, was to be given one of the 'drinks'; the steel pasted with oil and unguent was made red-hot in fire and then treated with one of the following: blood, ghee, water, .milk of mammal animals or fish-bile. Then this had to be sharpened. (BS. 50.23-25). Another process of heat-treatment was described as: ksare kadalya mathitena yukte dinosite payitamarasam yat samyak sitam casmani naiti khaड़ na canye lohesu api tasya kauntayam 'An iron weapon treated with a day-old drink made of the burnt powder of bananas (or its ribs) mixed with butter-milk, and then sharpened properly, will not break on stones, nor become blunt on other instruments' (BS.50.26).

VIII-23 Brhat Samhita reveals that during its era, the metallurgica activity in the country was intense. Gold was tested, melted, heate in the fire, hammered for testing its purity, purified nikasa santapa abhinivesaih kanakasya evam adhikatara amalikrta 439 to make sacrificial ladles, thrones, images etc. (BS.26.9; 43.12; 47.46). Varahamihira's statement shows that in India of his time, there were silver mines or rajatakara (BS.16.26). Red-hot copper, evidently used for casting into various shapes, was referred to : tapta tamraprabhabhah (6.13). References were made to the metalsmiths who fabricated weapons, and made a living working on fires: sastravati jivanti paro hutasanrtya 5.28, 10.4, 85.29 etc.). (BS. 5.35.See also Archaeological evidences such as copper images of Buddha, Mehrauli iron pillar made during Candragupta II's reign etc., substantiate the literary claims about the advanced state of Indian metallurgy during the Gupta era. Even later, Vana (7 th century A.D.) mentioned some of his companions as assayists and metallurgists. Hiuen-Tsang reported widespread use of noble metals and brass in India. The two subjects of astronomy and mathematics were deeply pursued during the Gupta era. One of the outstanding scientists, Aryabhata (born 476 A.D.), emphasized on direct observations and only four elements, de-emphasizing the fifth non-material akasa.

VIII-24 The Padartha-dharma-samgraha of Prasastapada was probably composed in the fifth century A.D. It was more than a commentary on the Vaisesikasutra of Kanada. This treatise gave a new exposition of the subject matter and important additions to the original work. Chandra's Dasa-padartha-sastra is available only in a Chinese version of 648 A.D. Prasastapada described the formation of gross bodies from the atoms (anu) through dyads (dvyanuka) and the structural arrangemer (vyuha) of the dyads to triads (tryanuka) which gives rise to differer qualities in a substance. In Prasastapada-bhasya was outlined the motion of impetus (Vega) which accounts for continued motion of a body. Some Buddhist scholars like Dignaga and Vasubandhu had questioned the Vaisesika postulates on atoms. But others like Sarvastivadin Subhagupta, who flourished in the second century A.D., defended atomism and the idea of a central atom combining with other atoms surrounding it. Dignaga had denied the existence of atom becaus it could not be separately perceived. Subhagupta argued: na anu amasam iti prahuh citta ca etasikanam ca sandigdhata bhavet eva that in that case one had to doubt the existence of mind and the mental phenomena as well!