Pramāṇa · Search · About · API

The Positive Sciences of the Ancient Hindus c4.s2: Chemistry in the Medical Schools of Ancient India

The Positive Sciences of the Ancient Hindus c4.s2

Language
English

Chemistry in the Medical Schools of Ancient India

c4.s2.1

As a matter of fact, long before the fifth century, probably as early as the first century A.D., the prevailing schools of medicine and surgery which were based on the Sánkhya teaching with a methodology derived from the Nyáya-Vaiseshika doctrine (*cf.* Charaka, Śárírasthána, Chap. I.; Vimánasthána, Chap. VIII.; also Susruta, Śárírasthána, Chap. I.) had founded an elaborate theory of inorganic and organic compounds, which equally admitted iso-Bhautic and hetero-Bhautic combinations. Like the Vedántists, Charaka held that each of the gross Bhútas (Mahábhútas) is a peculiar ultra-chemical compound of five original subtile Bhútas. In this sense, every substance is penta-Bhautic, but for purposes of chemical analysis and synthesis, *i.e.* considered with reference to the Mahábhútas, all substances in their chemical constitution belong to one or other of the following classes: mono-Bhautic, bi-Bhautic, tri-Bhautic, tetra-Bhautic, and penta-Bhautic. Compounds of different Bhútas, again, may combine to form more complex substances, and these in their turn higher compounds still, and so on in progressive transformation, as is more specially the case with organic substances and products.

c4.s2.2

*Physical Characters of the Bhútas.*—The prevailing physical characters of the different Bhútas and their isomeric modes are enumerated as follows:—

c4.s2.3

| Earth substances: | Heavy, rough, hard, inert, dense, opaque, exciting the sense of smell. |
| Ap substances: | Liquid, viscous, cold, soft, slippery, fluid, exciting the sense of taste. |
| Tejas substances: | Hot, penetrative, subtle, light, dry, clear, rarefied; and luminous. |
| Váyu substances: | Light, cold, dry, transparent, rarefied, impingent. |
| Ákása substances: | Imponderable (or light), rarefied, elastic, capable of sound (vibrations). |

c4.s2.4

गुरुखरकठिनमन्दस्थिरविशदसान्द्र-स्थूल गन्धगुणबहुलानि पार्थिवानि। द्रव-स्निग्धशीतमन्दमृदुपिच्छिलसररसगुणबहुलानि आप्यानि । उष्णतीक्ष्णसूक्ष्मल-घुरुक्षविशदरूपगुणबहुलानि आग्रेयानि । लघुशीतरूक्षखरविशद सूक्ष्मस्पर्शगुण-बहुलानि वायव्यानि । मृदुलघुसूक्ष्मश्लक्ष्णशब्दगुणबहुलानि आकाशात्मकानि ।—Charaka, Sárírasthána, Chap. XXVI. ; compare Susruta, Sútrasthána, Chap. XLI.

c4.s2.5

Charaka points out that the primary qualities or specific physical characters of the five Bhútas are tactile qualities, *i.e.* sensible to touch, *e.g.* hardness (or roughness) for Earth, liquidity (or yielding to pressure) for Ap, impelling or moving force (pressure) for Váyu, heat for Tejas, and vacuum (non-resistance, penetrability) for Ákása.

c4.s2.6

खरद्रवचलोष्णत्वं भूजलानिलतेजसाम् ,
आकाशस्याप्रतिघातो दृष्टं लिङ्गं यथाक्रमम् ।
लक्षणं सर्व्वमेवैतत् स्पर्शनेन्द्रियगोचरः ।
(Charaka, Sárírasthána, Chap. I.)

c4.s2.7

(*Cf.* the elaborate enumeration of physical characters quoted in Vijñána-bhikshu, Yoga-Vártika, Sutra 42, Pada I. ; also Varavara's commentary on Tattva-traya, Achit-prakarana.)

c4.s2.8

*The Mahábhútas—Mechanical Mixtures.*—Susruta notes that each of the gross Bhútas (Mahábhútas) is found mixed up with the other Bhútas—*e.g.*, the Mahábhúta Ákása is the receptacle (or vehicle) of air, heat-and-light, and water vapour ; the Mahábhúta Váyu, of water vapour, light-and-heat, and even fine particles of earth held in suspension ; the Mahábhúta Tejas, of earth particles in the shape of smoke, and also water vapour. (अन्योऽन्यानुप्रविष्टानि सर्व्वाय्येतानि निर्द्दिशेत्—Susruta, Sárírasthána, Chap. I. अन्ये पुनः अन्यथा व्याचक्षते । आकाशे

c4.s2.9

पवन-दहन-तोयानि। वायौ तेजोऽम्बुनी भूरपि अस्युताविशेषेण। भूमिरपि भूमादिरूपेण तेजसि। तेजोद्रव्ये पानीयमपि।—Dalvana on Susruta, *loc. cit.*)

c4.s2.10

Mono-Bhautic Earth substances:—Charaka and Susruta regard the following as Earth substances: gold, the five Lohas (silver, copper, lead, iron, and tin) and their "rust," arsenic, orpiment, various mineral earths and salts, sand, precious stones. (Charaka, Sútrasthána, Chap. I.; *cf.* also Susruta, Sútrasthána, Chap. I. पार्थिवाः सुवर्णरजतमणिसुक्तामनःशिलामृत्कपालादयः। सुवर्णस्य इह पार्थिवत्वमेवाङ्गीक्रियते गुरुत्वकाठिन्यस्थैर्यादिहेतुभिः। सूत्रे चादिग्रहणात् लोहमलसिकतासुधाहरिताललवणगैरिकरसाञ्जनप्रभृतीनां—Dalvana on Susruta, *loc. cit.*)

c4.s2.11

The salts include common salt, saltpetre, etc. Susruta mentions the alkalis, borax, natron, Yavakshára (carbonate of potash), etc. The Audbhida salt, an inflorescence of the soil, stands for *reh* (औद्भिदं पांषुलवणं यज्जातं भूमितःस्वयम्).

c4.s2.12

Of these Earth substances some were known to be compounds, *e.g.* the chemical salts of the metals, collyrium, etc. Susruta describes the preparation of the metallic salts. The leaves of the metals were pasted over with the salts, and then roasted (अयस्कृति, Chikitsásthána, Chap. X.). These metallic salts are therefore mono-Bhautic Earth compounds. Susruta also gives the preparation of mild and caustic alkalis (Sútrasthána, Chap. XI.).

c4.s2.13

Origin of precious stones.—Some hazarded the guess that the precious stones are rocks (or earths) metamorphosed by natural process in the course of ages (Varáhamihira—केचित् भुवः स्वभावात् वैचित्र्यं प्राडुरुपलानाम्। Utpala notes—रत्नद्रूपत्वं प्राप्ताः कालान्तरेण।).

c4.s2.14

Ap substances, simple and compound :—

c4.s2.15

Susruta, following Charaka, enumerates various classes of Ap substances (द्रवद्रव्य) as follows: waters, acids, milks, curds, butters, oils (vegetable as well as animal), fats, honeys, molasses, alcoholic liquors, urines, etc.

c4.s2.16

Pure Ap (Mahábhúta) is tasteless, and the six tastes are developed when the Mahábhúta Ap enters into combination, mechanical or chemical, with other Mahábhútas. Susruta notes that various kinds of Earths are dissolved in the waters of different localities, and where the particles so dissolved are predominantly earthy, the water tastes acid or salt; where predominantly watery, the resulting taste is sweet; where the Earth-particles are mixed up with Tejas, the water tastes pungent or bitter, etc. Such is the case with mechanical mixtures. In the case of bi-Bhautic or tri-Bhautic compounds Charaka mentions that substances with Mahábhúta Ap predominating in their composition taste sweet; with Mahábhútas Earth and Tejas predominating, acid; with Mahábhútas Ap and Tejas predominating, salt; with Mahábhútas Váyu and Tejas predominating, pungent; with Mahábhútas Váyu and Ákása predominating, bitter; and with Mahábhútas Váyu and Earth predominating, astringent. (Charaka, Sútrasthána, Chap. XXVI. ; *cf.* Susruta, Sútrasthána, Chap. XLII.)

c4.s2.17

In fact, with the exception of Susruta’s waters, which are mechanical mixtures, or rather solutions, all these Ap substances are organic products, and, as such, penta-Bhautic, *i.e.* compounded of all the five Mahá- bhútas, and the particular "taste" which is developed depends on the relative proportion of the Mahábhútas and the predominance of one or more of them in the penta-Bhautic compound in question.

c4.s2.18

*Qualities of Compounds.*—The isomeric modes of each Mahábhúta have specific colours, tastes, etc., due to their structure, *i.e.* the arrangement of their atoms, and the physico-chemical characters of compounds, whether of the same or of different Mahábhútas, result from the collocation in unequal proportion of the different forces latent in the atoms of the component substances. Charaka adds that the varied forms (textures) and colours of organic substances, whether vegetable or animal, are derived in the same way. (एवमेतेषां रसानां षट्त्वमुपपन्नं न्यूनातिरेकविशेषात् महाभूतानाम्। भूतानामिव स्थावरजङ्गमानां नानावर्णोक्कृतिविशेषाः।)

c4.s2.19

Susruta ignores Charaka's distinction between Mahábhúta and subtile Bhúta, and views every substance as in reality penta-Bhautic, and it is only the relative predominance of a particular Bhúta or Bhútas in any substance that determines its class. (पृथिव्यप्तेजोवाय्वाकाशानां समुदायात् द्रव्याभिनिवृत्तिः। उत्कर्षस्तु अभिव्यञ्जको भवति इदं पार्थिवं इदं व्याप्यं इदं तैजसं इदं वायव्यं इदं आकाशीयमिति।—Susruta, Sútrasthána, Chap. XLI.)

c4.s2.20

*The Extant Charaka and Susruta—Succession of Medical Authorities.*—The extant Charaka and Susruta, the sources of our present information regarding the progress of scientific knowledge in the medical schools of ancient India, are both redactions of original authorities. The extant Charaka is a redaction by Dridhabala of the genuine Charaka Samhitá, which was itself a redaction by Charaka of the original work of Agnivesa, the disciple of Átreya Punarvasu as distinguished from Krishnátreya and Bhikshu Átreya, also well-known medical authorities. The extant Susruta is a redaction by Nágárjuna of an original work (Vriddha Susruta) by Susruta, the disciple of Dhanvantari. That Charaka preceded Susruta is almost certain. Nágárjuna was probably earlier than Dridhabala. At any rate, Dridhabala imported into Charaka much of the surgical knowledge which had till then been the traditional heritage of the Susruta school. And in the matter of the surgical treatment of certain diseases, the genuine Dridhabala is often as advanced as Susruta’s redacteur himself. The latter was probably identical with the alchemist Nágárjuna (Siddha Nágárjuna), the metallurgist Nágárjuna (author of a treatise on metallurgy, Lohasástra), and the Buddhist Nágárjuna, author of the Mádhyamikasútravritti. Charaka and Susruta continued to receive additions after Dridhabala and Nágárjuna, and even after Vágbhata, but the whole of the extant Charaka is probably much earlier than the commentator Chakrapáni, and the whole of the extant Susruta earlier than Dalvana, the commentator, and Mádhava, the author of Rugvinischaya. The extracts in Vágbhata make it certain that the passages I have quoted or shall quote from the Sútrasthána and Śárírasthána of Charaka and Susruta cannot be later than the sixth century of the Christian era.

c4.s2.21

*Preparation of Chemical Compounds.*—The knowledge of chemical compounds and of their preparation continued to make progress in the Charaka and Susruta schools. The great metallurgist, Patañjali, in his treatise on Metallurgy (लोहशास्त्र), gave elaborate directions for many metallurgic and chemical processes, especially the preparation of the metallic salts, alloys, and amalgams, and the extraction, purification, and assaying of metals. Probably it was Patañjali who discovered the use of the mixtures called Vidas, which contained aqua regia or other mineral acids *in potentia*. Unfortunately Patañjali's *magnum opus* appears to have been lost, but extracts from it are frequently found in mediæval works on Medicine and Rasáyana which leave no doubt as to its remarkable scientific value. The metallurgist Nágárjuna advanced the knowledge of chemical compounds by his preparations of mercury. The Harshacharita, in the seventh century, relates a fable concerning this Nágárjuna, and speaks of him as a friend and contemporary of Sátaváhana. The relative priority of Patañjali and Nágárjuna is a vexed question in the history of metallurgy. That Nágárjuna's Lohasástra was earlier than the final redaction of Patañjali will appear from the following circumstances:—(1) Chakradatta in his summary of Nágárjuna mentions that the chemical process of testing pure iron must be repeated twice before it can be regarded as decisive, whereas Śivadása Sen's extract from Patañjali shows that the latter directed the process to be repeated seven times; (2) Patañjali in the Abhraka-vidhi (mica operation) adds mercury, which in this particular operation is wanting in Nágárjuna's recipe (*cf.* Chakradatta, and Patañjali as reported in the Yogaratnákara-samuchchaya); and (3) Nágárjuna is quoted in the earlier compilations, Patañjali in the later.

c4.s2.22

*Chemical Industries.*—Early in the sixth century, Varáhamihira in the Vrihat Samhitá gives several preparations of cements or powders called Vajra-lepa, “cements strong as the thunderbolt”; and there was ample use for these in the temple architecture of the Buddhist period, the remains of which bear testimony to the adamantine strength of these metal or rock cements. (प्रासादहर्म्यवलभीलिङ्गप्रतिमासु कुड्यकूपेषु सन्तप्तो दातव्यो वर्षसहस्रायुतस्थायी। Chapter LVI., *ibid.*) Varáhamihira also alludes to the experts in machinery (यन्त्रविदः, यन्त्रज्ञाः) and the professional experts in the composition of dyes and cosmetics (रागगन्धयुक्तिविदः Ch. XVI., also Ch. XV.). I would also refer to the interesting chapter on Perfumery (Ch. LXXVI.) where Varáhamihira gives various recipes for artificial imitations of natural flower-scents, as of the essence of Vakula, Utpala, Champaka, Atimuktaka, etc., arranges compound scents in a sort of scale according to the proportions of certain ground essences used in their preparation, and determines by the mathematical calculus of combination (लोधकप्रस्तार) the number of variations of the different notes in this scale. To these classes of professional experts were due three of the great Indian discoveries in the chemical arts and manufactures which enabled India to command for more than a thousand years the markets of the East as well as the West and secured to her an easy and universally recognised pre-eminence among the nations of the world in manufactures and exports: (1) the preparation of fast dyes for textile fabrics by the treatment of natural dyes like Mañjishthá with alum (तुवरी मंजिष्ठा रागवन्धिनी) and other chemicals (*e.g.* sulphate of iron) also cow-dung (*cf.* the "cow-dung substitute," Roscoe) ; (2) the extraction of the principle of indigotin from the indigo plant by a process which, however crude, is essentially an anticipation of modern chemical methods ; and (3) the tempering of steel in a manner worthy of advanced metallurgy, a process to which the mediæval world owed its Damascus swords. It was this applied chemistry much more than handicraft skill which gave India her premier position in the Middle Ages and earlier (indeed from Pliny to Tavernier) in exports and manufactures ; for in handicraft skill, as in design and workmanship, great as were her merits, India came to be surpassed by her disciples China and Japan.

c4.s2.23

The Vásavadattá and the Dasakumára Charita in the sixth century allude to the preparation of a mass of fixed or coagulated mercury (पारदपिण्डइव कालधातुवादिनः—वासवदत्ता) ; a chemical powder, the inhalation of which would bring on deep sleep or stupor (योगचूर्णं—दशकुमारचरित) ; a chemically prepared stick or wick for producing light without fire (योगवर्तिका—दशकुमारचरित) ; and a powder which, like anæsthetic drugs or curare, paralyses sensory and motor organs¹ (स्तम्भनचूर्णमिव इन्द्रियाणाम्—वासवदत्ता—धीन्द्रियकर्मेन्द्रियाणां—Darpana). Vrinda (*circa* 950 A.D.) notices the preparation of sulphide of mercury (रसामृतचूर्ण), composed of one part of sulphur and half its weight of mercury; and also of cuprous sulphide (पर्पटिताम्र). Chakrapáni (*circa* 1050 A.D.) mentions the preparation of the black sulphide of mercury "by taking equal parts of mercury and sulphur."

c4.s2.24

¹ This last interpretation is doubtful ; but in any case the familiar use of a technical term of alchemistry like Stambhana-churnam (fixation-powder) shows that already in the sixth century this branch of knowledge was widely cultivated.

c4.s2.25

The *Rasárnava* (*circa* 1200 A.D.) notices the colours of metallic flames, probably after Patañjali—*e.g.* copper gives blue flame; tin, pigeon-coloured; lead, pale; iron, tawny; blue vitriol, red. It may be noted that the *Rasárnava* regards mercury as a penta-Bhautic substance.

c4.s2.26

The *Rasaratna-samuchchaya* divides the mineral kingdom (Earth substances, simple and compound) into the following classes: (1) The eight Rasas: mica, pyrites, bitumen, blue vitriol, calamine, etc. (2) The eight Uparasas (useful in operations of mercury): sulphur, red ochre, green vitriol, alum, orpiment, realgar, collyrium, and medicinal earth, to which may be added the eight Sádhárana Rasas, sal-ammoniac, cowrie, cinnabar, rock vermilion, etc. (3) The gems diamond, emerald, sapphire, cat's-eye, sun-stone, moon-stone, pearl, etc. (4) The metals gold, silver, iron, copper, lead, tin, and the alloys brass and bell-metal. Other Earth substances are six salts, three alkalis, mineral earths, and several poisons.

c4.s2.27

*Chemical Compositions and Decompositions—Metallurgic Processes.*—In these writings¹ we frequently come across instances of chemical composition and decomposition by processes, more or less crude, of calcination, distillation, sublimation, steaming, fixation, etc. (भस्मीकरण, अधःपातन, उर्द्धपातन, स्वेदन, स्तम्भन, etc.), *e.g.* the preparation of perchloride of mercury by taking common salt and mercury (रसकर्पूर—पारदस्य श्‍वेतभस्मीकरणे चन्द्रिकाकारः); of sulphide of mercury (हिङ्गुल) by taking sulphur and mercury; of Sindúra from lead (सिन्दूरं नागसम्भवम्—Amarakosha, sixth century A.D.); of the medicinal compounds Svarnasindúra and Rasasindúra with mercury, sulphur, and gold, where gold may have been fancied to influence the resulting compound in some mysterious way, either as a "dynamic" or as a catalytic; also the extraction by chemical decomposition of mercury from sulphide of mercury (हिङ्गुल); of copper from sulphate of copper (तुत्थ, सस्यक) by heating this substance with one-fourth of its weight of borax (Rasaratna-samuchchaya,—*cf.* Bhávaprakása, तुत्थं तु ताम्रोपधातु किञ्चित् ताम्रेण तद्भवति); of zinc (यशद, जसद्) from calamine (रसक); of copper from pyrites (माक्षिक, विमल), etc. (though the golden pyrites were supposed to be a semi-metal of gold, containing some gold along with the essence of copper); the purification of mercury by repeated distillation from lead and tin with which it was wont to be adulterated in the market. The various metallurgic processes described are—extraction, purification, killing (formation of oxides, chlorides, and oxy-chlorides for the most part), calcination, incineration, powdering, solution, distillation, precipitation, rinsing (or washing), drying, steaming, melting, casting, filing, etc., to all which each of the known minerals was successfully subjected by the use of apparatus and reagents and the application of heat in different measures (खरपाक, मध्यमपाक, and मृदुपाक)—methods which, if often crude, especially from the absence of independent and isolated mineral acids, were yet in several instances remarkably simple and effective, and which, after all, by the use of various Vidas potentially containing mineral acids (aqua regia, sulphuric acid, hydrochloric acid, etc.), virtually accomplished the practical ends kept in view. To these were added several special processes for mercury (*e.g.* fixation), bringing up the number of mercurial operations to nineteen.

c4.s2.28

¹ From Patañjali's and Nágárjuna's Lohasástra (*circa* 300–500 A.D.?) downwards—(practically everything material in the enumeration that follows was discovered by the end of the sixth century A.D.).

c4.s2.29

It may be noted that the mixtures called Vidas, which potentially contained dilute mineral acids, were regularly employed not only in killing the metals (forming their oxides and chlorides), but—what is of fundamental importance—for purposes of chemical decomposition of metallic salts, etc., and the extraction and purification of metals.

c4.s2.30

*Organic Compounds.*—Organic compounds are either vegetable or animal substances (स्थावर जङ्गम भूत). The molasses, the fermented liquors, the saps and juices of plants, fruit acids, vegetable ashes and alkalis, together with the tissues of plants, are vegetable compounds (औद्भिद, स्थावर भूत). Honey, milk, curd, butter, fat, bile, urine, and other excreta, together with the organs and tissues of animals, are animal substances. Charaka notices vegetable as well as animal oils. The viscous (oily) substances are classed under four heads—butters, oils, fats, and marrows (सर्पिस्तैलं वसा मज्जा स्नेहो दृष्टश्चतुर्विधः). Salt may be either mineral or vegetable salt.

c4.s2.31

Susruta divides poisons into two classes—vegetable and animal, but several poisons expressly termed mineral poisons (धातुविष) are included in the first class.

c4.s2.32

All organic substances, whether animal or vegetable, are penta-Bhautic, being compounded of greater or less proportions of the five Mahábhútas.

c4.s2.33

Taking the human body, Charaka finds that the fœtus is composed of sixteen organic substances, viz. four composing the sperm-cell which comes from the male; four composing the germ-cell which comes from the female; four added by the transformation of the nutritive material; and finally, four kinds of subtile matter, which together form the vehicle of the conscious principle. As to the four organic substances which compose the sperm-cell, or the other four which compose the germ-cell, it is not clear whether in Charaka's view they are also in their turn compounded of less complex organic substances, or whether their constituent elements are inorganic penta-Bhautic compounds.

c4.s2.34

The tissues that appear in the course of development of the fœtus are further transformations (higher compounds) of these fœtal substances. All the component substances of the body are penta-Bhautic compounds, though sometimes they are assigned to the particular Bhútas which predominate in their composition, *e.g.* bile to Tejas, lymph, chyle, blood, fat, urine, sweat, and other secretions to Ap, and skin, flesh, bones, nails, etc., to Earth. (शुक्रं वाव्वग्न्यभूम्यद्गुणपादवत् ।—गर्भस्य चत्वारि चतुर्विधानि भूतानि मातापितृसम्भवानि आहारजानि आत्मकृतानि चैव *et seq.*—Charaka, Śárírasthána, Chap. II., *vide* also Charaka, Śárírasthána, Chap. VII., *cf.* Gaṅgádhara's Jalpakalpataru. पित्तं तृतीयं भूतं शरीरारम्भकतेजःप्रधानपञ्चभूतविकारात्मकं तेजःस्वरूपं अग्निसंज्ञम् । कफश्चतुर्थं भूतमापः शरीरारम्भकसोमप्रधानपञ्चभूतविकारविशेषः । शरीरं तु पञ्चमहाभूतविकारसमुदायात्मकम् । *Cf.* Charaka, Śárírasthána, Chap. IV., मातृजादयोऽपि यस्य महाभूतविकाराः ।)

c4.s2.35

*Formation of Molecular Qualities in Chemical Compounds.*—The Charaka school, which we have seen was an offshoot of the Sánkhya (*cf.* Charaka, Vimánasthána, Chap. VIII., यथा वाऽऽदित्यः प्रकाशकः तथा सांख्यवचनं प्रकाशकमिति), supplemented the above account of inorganic and organic compounds with a characteristically Sánkhya explanation of the formation of molecular qualities by chemical combination. In Charaka's view, the colours, tastes, etc., of the molecules of chemical compounds result from the collocation in unequal proportion and unstable equilibrium of the different forces latent in the atoms (Paramánus) themselves. (एवमेतेषां रसानां षट्त्वमुपपन्नं न्यूनातिरेकविशेषात् महाभूतानां । भूतानामिव स्थावरजङ्गमानां नानावर्णाकृतिविशेषाः ।—Charaka.)

c4.s2.36

*Chemistry of Colours.*—As an interesting example of the way in which a follower of Charaka would account for the colours of chemical compounds, I may note the explanation given by the late Gańgádhara Kavirája Kaviratna in the Jalpakalpataru, a commentary on the Charaka-Samhitá, published at Calcutta in 1869, premising that the Kavirája's view is pure and genuine Charaka doctrine. Gańgádhara begins with a simple statement. The qualities of the atom, he writes, tend to produce similar qualities in the molecule. A molecular quality is therefore the result of the conjunction or opposition, as the case may be, of the atomic tendencies. When, for example, the five Bhútas combine to produce an organic compound (the human body), Tejas, Ap, and Earth tend to produce red, white, and black respectively, but in the body (compound substance) the yellow colour may happen to be produced as the result of these tendencies in that particular proportion and collocation. The point to note here is that the molecule forms a fresh collocation, *redistributes the Mass and Energy*, and sets up new forces in the system, which coming into play modify the potencies (or tendencies) in the component atoms, and thus determine the resultant. This is elaborated into a curious but complete theory of the colours of chemical compounds.

c4.s2.37

The colours (and other qualities) of a simple substance (an isomeric mode of any Bhúta) are the result of the potencies lodged in that particular collocation of Mass, Energy, and Essence. Now when two such substances unite, their colours, etc., tend to be produced, but the combination brings on a fresh distribution of Energy, Mass, and Essence, and the forces thus set free may powerfully modify or even extinguish the separate tendencies or potencies of the component simple substances. For example, when we prepare a collyrium by mixing equal parts of sulphur and mercury (the black sulphide of mercury) we find the resulting compound black. To explain this it has to be remembered that each of the substances (sulphur and mercury) contains Sattva (Essence), Rajas (Energy), and Tamas (Mass) in different proportions, and that predominant Tamas (Inertia, Mass) always produces black, predominant Sattva (Essence) white, and predominant Rajas (Energy) red. Now in the black sulphide of mercury the white of the mercury tends to produce white, and the yellow of the sulphur yellow, and if these tendencies were not obstructed the result would be a mixed colour. But, in the particular collocation in question, the Tamas of the mercury becomes intensive (तीव्र), and the black of the now intensive Tamas extinguishes the white in the uncompounded mercury, which was due to prevailing Sattva, as well as the yellow of the uncompounded sulphur, which was due to the combined operation of white-producing Sattva and red-producing Rajas. Again, when, with proper apparatus and by the application of heat, we combine mercury and sulphur to produce the red sulphide of mercury, the resulting colour is explained by the fact that in this new collocation the Rajas (Energy)—probably of the mercury, though Gaṅgādhara does not specify—becomes intensive (तीव्र), and extinguishing both the white-producing Sattva of the mercury and the yellow-producing Sattva-Rajas of the sulphur, imparts a red colour to the compound. In these cases, as also in the formation of red by mixing powdered turmeric with lime, *i.e.* whenever a new colour is produced in the compound, it is to be explained by the dominance of Tamas, Rajas, or Sattva, or their combinations, and the extinction of the uncompounded tendencies (or potencies) by the forces set free in the new collocation. But there are other cases where the colour of the compound is a mixed colour resulting from the colours of the combining substances, *e.g.*, when sulphide of mercury and calcined tin are mixed, the resulting colour is evidently a mixed one (Pátala, pink), which is easily explained by the colours of the component elements (the red of the sulphide of mercury and the white of the calcined tin); in the same way, in a mechanical aggregate, as in a piece of cloth, the colour is white where the threads are white.

c4.s2.38

तत्रकार्यारम्भे पृथिव्यादिद्रव्यावस्थागुणा गन्धादयः खलु खसजातीयं गन्धविशेषादिकं आरभमाणाः यदारभ्यमाणं स्वस्वविजातीयं कार्यं स्यारम्भकं कारणञ्च शङ्खारादिस्यं गुणांशं उभयथा कुत्रचित् हत्वा कुत्रचित् न हत्वा स्वजातीयं गुणविशेषं आरभन्ते । यथा पारदगन्धकयोः संयोगे कज्जलीभूतद्रव्ये पारदस्यः शुक्लः शुक्लविशेषं आरभमाणः गन्धकस्यपीतः पीतमारभमाणः पारदस्यतीक्ष्णेन तैक्ष्ण्यमारभमाणेन विरोधिना बध्यते । सङ्गेनैव शौक्ल्यं सत्त्वगुणयोनिकं तमोगुणयोनिकेन तैक्ष्ण्येन विरोधिना बध्यते । गन्धकस्यपीतस्यौ च लोहितशुक्लौ रजःसत्त्वयोनिकौ वध्येते । तयोः शुक्ललोहितवधे तैक्ष्ण्यसमानयोनिः कृष्णः अभिव्यज्यते । इति पारदगन्धकोभयात्मके कार्य्ये श्वेतपीतमेलनेन सम्भाव्यं कार्य्यं यद्वर्णं तत् तीक्ष्णगुणेन वध्यते, तत्रकारणं शुक्ललोहितं हत्वा । एवं हिङ्गुले पारदगन्धकाभ्यामारभ्यमाणे यन्त्रविशेषे वह्निना पच्यमाने रजोबहुलयोगिकेन तीक्ष्णेन सत्त्वतमोगोनिकौ शुक्लकृष्णौ वध्येते । पारदस्यशुक्लङ्गन्धकस्यपीतमेलनेन सम्भाव्यं कार्य्यं वर्णं च वध्यते । रजोयोनिकलीहित्यं च अभिव्यज्यते इति । एवं हरिद्राचूर्णसंयोगेऽपि लीहित्यं अभिव्यज्यते चूर्णस्यतैक्ष्ण्येन हरिद्रास्यशुक्लकृष्णवधे । अथ भवधे यथा—हिङ्गुलवङ्गभस्मसंयोगे श्वेतलोहितवर्णमेव उभयात्मकं भवति पाटलवर्णं, न च तत्र हिङ्गुलस्य लौहित्यं वङ्गभस्मस्य शौक्ल्यं च केनापि वध्यते । एवं शुक्लसूत्रनिर्मितपटस्य शौक्ल्यमेव ।

c4.s2.39

(Jalpakalpataru, Sútrasthána of Charaka, pp. 198–200; edition published by Bhubanachandra Basák, Calcutta, Samvádaratnákara Press, Samvat 1925.) This is quite in a line with Charaka's explanation of the tastes of chemical compounds which has been already noticed.

c4.s2.40

*Parináma-váda versus Árambha-váda.*—Charaka's view of the formation of a new quality or a new substance is based on the Sánkhya teaching as to the conservation and transformation of Energy, and brings chemical synthesis in a line with evolutionary change (परिणाम). On this view, a new substance may arise by spontaneous or isomeric change, *i.e.* by the interplay of Energies within the system of any given substance, in the absence of any action from without. New qualities like new substances are only readjustments of the old, and continual changes are going on by spontaneous disintegration and recombination. Opposed to this evolutional view of chemical synthesis is the Nyáya-Vaiseshika doctrine of Árambha-váda, according to which no change of substance or quality, no effect, in short, can take place except by the action of one component element (substance or quality) on another. A binary molecule, for example, cannot possess any "specific quality" (विशेषगुण) of a kind not represented in each of the two component atoms. In the cosmic process no atom can exist free and uncombined with another atom, and every "specific quality" in a substance can be ultimately analysed into the union of two "specific qualities" *of the same class* in two ultimate particles which cannot be further divided. A single colour, smell, or taste in a single particle, until it can link itself on to another specific quality *of its own class* in a second particle, cannot characterise any substance formed by the union of these particles as material causes. Hence an Earth-atom cannot unite with an Ap-atom to form a new substance of which both the particles must be equally regarded as material causes. At any rate, such a compound, if effected, would be smell-less, as of the two constituent atoms only one, viz. the Earth-atom, possesses smell. A compound of Earth and Váyu would be smell-less, colourless, and tasteless, and so on. The Nyáya-Vaiseshika does not deny that there may be compounds of different Bhútas, nor does it deny the causal operation of specific qualities as efficient or energising (dynamic) causes (उपष्टम्भक, निमित्तकारण), but it refuses to place these compounds on the same footing as compounds of isomeric modes of the same Bhúta; and it accepts the "material" causality in such cases of only one of the Bhútas, regarding the others as co-efficients (निमित्तकारण).

c4.s2.41

The earlier Sánkhyas including the medical schools of ancient India brushed all this aside as a distinction without a difference. The Vedántists, as we shall presently see, flouted this doctrine of Árambha-váda. The Jainas, in opposing this Vaiseshika view of atomic combination, hit upon a solution of the problem of chemical affinity. Others, again, found out a *via media*. They held, as we learn from the reports of Udyotakara in the Nyáya-vártika, and of Váchaspati Misra in the Tátparyyatíká, that a molecule of the structure EA (one atom of Earth and one of Ap) would exhibit some variety of colour and taste resulting from the joint action of the atoms and of their several colours and tastes. But as in the combination EA only the Earth-atom possesses smell, and the Ap-atom is smell-less, and as moreover no quality in a compound substance can result except from the joint action of the similar (potential) qualities of at least two component elements, it follows that a molecule of the structure EA would not manifest the energy of smell potentially contained in the Earth-atom. Hence, admitting the combination EA for a smell-less compound, the upholders of this view would suppose a molecule of the type E₂A (*i.e.* two atoms of Earth and one of Ap) to explain any bi-Bhautic compound of Earth and Ap (like the plant saps and fruit juices) which exhibits smell in addition to the peculiarities of colour and taste. *Cf.* Váchaspati’s comment on Udyotakara’s refutation of this view:—

c4.s2.42

अयमभिसन्धिः । पृथिव्याप्यपरमाणू तावदेकं द्वयणुकमारभेते तयोः रूपरसस्पर्शवत्वेन तदारम्भसम्भवे अपि गन्धवत्त्वाभावप्रसङ्गात् । रूपं पार्थिवाणुसमवेतस्य गन्धस्य एकत्वेन अनारम्भकत्वात् नापि पार्थिवपरमाणुद्वयं एकश्चाप्यसीयपरमाणुः इति त्र्यणुकारम्भकत्वे गन्धवत्त्वोपपत्तिः इति साम्प्रतं । परमाणूनां बहूनां अनारम्भकत्वात् । तथाहि त्रयः परमाणवः न कार्य्यमारभन्ते ।

c4.s2.43

*Measures of Time and Space*—*Size of Atoms.*—The Siddhánta-Śiromani gives the following measures of Time:—

c4.s2.44

| 30 Kshanas (क्षण) = 1 day, | 30 Káshthás = 1 Kalá, |
| 2 Ghatikás = 1 Kshana, | 18 Nimeshas = 1 Káshthá, |
| 30 Kalás = 1 Ghatiká, | 30 Tatparas = 1 Nimesha, |
| \multicolumn{c}{and 100 Trutis = 1 Tatpara.} |

c4.s2.45

This makes a Truti of time equal to 1/33750 of a second, which is nearly the measure of the Paramánu of time as given in the Vishnu Purána (*vide* Bháskara’s Siddhánta-Śiromani—**कालमानाध्याय**).

c4.s2.46

The above measures were in use among the astronomers, but the physicists computed according to the following table given both in Udayana's Kiraṇávali and Śrídhara's Nyáya-Kandalí :—

c4.s2.47

30 Muhúrtas = 1 day (24 hours),
30 Kalás = 1 Muhúrta, 2 Lavas = 1 Nimesha,
30 Káshthás = 1 Kalá, 2 Kshanas = 1 Lava.
18 Nimeshas = 1 Káshthá,

c4.s2.48

खण्वयं लवः प्रोक्तो निमेषस्तु लवद्वयम्,
अष्टादशनिमेषास्तु काष्ठा त्रिंशत्तु ताः कला ।
त्रिंशत्कला मुहूर्तः स्यात् त्रिंशद्यात्र्यहनी च ते ।
(Udayana, Kiraṇávali.)

c4.s2.49

This makes 1 Kshana of the Nyáya-Vaiseshika equal to 2/45 of a second. The Nyáya assumes that the unit of physical change (or the time occupied by any single antecedent step in a causal series before the succeeding step is ushered in) is equal to a Kshana (or 2/45 of a second). The astronomers were familiar with far smaller measures of time. The astronomical Truti of time measures about the thirty-four-thousandth part of a second. This is of special value in determining the exact character of Bháskara's claim to be regarded as the precursor of Newton in the discovery of the principle of the Differential Calculus, as well as in its application to astronomical problems and computations. This claim, as I proceed to show, is absolutely established; it is indeed far stronger than Archimedes' to the conception of a rudimentary process of Integration. Bháskara, in computing the "instantaneous motion" (तात्कालिकी गति) of a planet, compares its *successive* positions, and regards its motion as constant during the interval (which of course cannot be greater than a Truti of time, though it may be indefinitely less). This Tátkálika motion is no other than the differential of the planet's longitude, and Bápudeva Śástrí claims that both the conception of the instantaneous motion and *the method of determining it* plainly show that Bháskara was acquainted with the principle of the Differential Calculus. On the data before him, Mr. Spottiswoode remarks that Bápudeva Śástrí "overstates the case." Bháskara "makes no allusion to one of the most essential features of the Differential Calculus, viz. the infinitesimal magnitude of the intervals of time and space therein employed. Nor indeed is anything specifically said about the fact that the method is an approximate one." "With all these reservations," Mr. Spottiswoode continues, "it must be admitted that the formula he establishes and the method of establishing it bear a strong analogy to the corresponding process in modern mathematical astronomy" (viz., the determination of the differential of the planet's longitude—by no means the first step in transcendental analysis or in its application to astronomy). And Mr. Spottiswoode concludes by stating that mathematicians in Europe will be surprised to learn of the existence of such a process in the age of Bháskara (*circa* 1150 A.D.—born 1114 A.D.). Mr. Spottiswoode's second objection, that Bháskara does not specifically state that the method of the Calculus is only approximative, cannot be taken seriously. The conception of limit and the computation of errors came late in the history of the Calculi of Fluxions and Infinitesimals. For the rest, Bháskara introduces his computation expressly as a "correction" of Brahmaand one Pala as much as four *Suvarnas* or Tolás. A Pala of gold therefore weighs 320 *Krishnalas* (Manu, Chap. VIII. ; Vishnu, Chap. IV. ; and Yájñavalkya, Chap. I.).

c4.s2.50

A Máshá of gold therefore would weigh 6 9/16 grains ; a Tolá, 105 grains (in current practice it weighs nearly double, as I have stated); and a Pala, 420 grains Troy.

c4.s2.51

The measures for silver were the following :— 1 silver Máshá = 2 *Krishnalas*, 1 *Dharana* = 16 silver Máshás, and 1 Pala = 10 *Dharanas*. A Pala of silver would therefore weigh 320 *Krishnalas*. In other words, the Pala was a fixed measure of weight, and was equal to about 420 grains Troy, or double this if we take the *Krishnala* of current practice.

c4.s2.52

A Pala, which equals 320 *Krishnalas*, was sub-divided by 4, 16, and 5 successively for gold, and by 10, 16, and 2 successively for silver. A *Suvarna* (or Tolá) of gold corresponds roughly to a *Dharana* of silver, and a gold Máshá to a silver Máshá, but the sizes (or volumes) are not the same, and we must not therefore conclude that gold was supposed to be heavier than silver in the proportion of 5 to 2.

c4.s2.53

We find that 1296 *Trasarenus* equal one *Krishnala*. A *Trasarenu*, as a measure of weight, therefore, is the equivalent of 7/6912 of a grain Troy, or double this according to current measures.

c4.s2.54

But the *Trasarenu* of physics is a different conception. It stands for the *minimum visibile*, *i.e.*, as the physicists define it, that which is *just discernible* as a glancing particle in the slanting beams of the morning (or afternoon) sun coming into a dark room through a chink or orifice of a window. This is a measure of size (or rather *stimulus limen*).

c4.s2.55

*Measures of Capacity.*—Here the standard was furnished by the Kudava (कुड़व), a vessel described as 3 Aṅgulis long, 4 Aṅgulis broad, and 1½ Aṅguli deep, with a cubical capacity of 13½ cubical Aṅgulis. 4 Kudavas = 1 Prastha, 4 Prasthas = 1 Áḍhaka, 4 Áḍhakas = 1 Droṇa, and 4 Droṇas = 1 Khárí or Bhára.

c4.s2.56

24 Aṅgulis make 1 Hasta, cubit, which may be taken to be 18 or 19 inches. A Kudava was divided into 4 Palas, and there can be no doubt that originally water of the weight of 4 Palas was found to be actually contained in a vessel of the cubical capacity of a Kudava. If we take the ancient cubit to have been 19 inches, the Kudava would contain nearly 4 Palas of distilled water at 30° Centigrade. On a cubit of 18 inches, the Kudava would contain about 3¾ Palas.

c4.s2.57

The Kudava in current medical practice is supposed to represent a cubical vessel, each side being 4 Aṅgulis. This would give a capacity of 27 cubic inches, if we take the modern cubit of 18 inches. The Kavirájas take a Kudava to contain 8 Palas of water, and as 1 Pala = 320 Krishnalas, and 80 Krishnalas are now taken to be equal to 210 grains Troy, a vessel of a capacity of 27 cubic inches is accordingly supposed to contain about 6,720 grains Troy—which is not very wide of the mark, being about 1·3 per cent. short for distilled water at 86° Fahrenheit or 30° Centigrade.

c4.s2.58

*Size of the Minimum Visibile; Size of an Atom.*—The supposed thickness of the just-discernible mote in the sunbeam (called a Paramánu in Technology, Silpasástra, and a Trasarenu in Natural Philosophy) follows directly from Varáhamihira’s table:—8 Paramánus make 1 Rajas (or Ratharenu,—*cf.* the Manasara), 8 Rajas make 1 Válágra (filament of hair), 8 Válágras make 1 Likshá, 8 Likshás make 1 Yúká, 8 Yúkás make 1 Yava, 8 Yavas (the Manasara has 4) make 1 Anguli (superior), 24 Angulis make 1 Hasta (cubit, lesser cubit, 18 inches). The thickness of the *minimum visibile* (the finest perceptible mote in the slanting sunbeam) is therefore taken to be 3.2⁻²⁰, or 1/349525 of an inch. The volume of a spherical Trasarenu (or Paramánu of the Silpasástra) would therefore be 4/3.π.3³.2⁻⁶³ of a cubic inch. It may be here noted that such a Trasarenu is supposed in the medical schools to contain 30 chemical atoms (Paramánus of Natural Philosophy) according to one estimate, or 60 according to another. The size of an atom must then have been conceived to be less than π.3.5⁻¹.2⁻⁶² of a cubic inch.¹ (परमाणुरजोवालाग्रलिक्षायूकं यवोऽङ्गुलं चेति अष्टगुणानि यथोत्तरम् अङ्गुलमेकं भवति संख्या.—Varáhamihira, Vrihatsamhitá, Chap. LVII., Śloka 2. जालान्तरगते भानौ यदणुतरं दर्शनं रजो याति तद्विद्वात् परमाणुं प्रथमं तद्धि प्रमाणानाम् ।—*ibid.*, Śloka 1.—*Cf.* Utpala, तत्परमाणुं नाम प्रमाणं जानीयात् । प्रमाणानां सर्वेषां तत् प्रथममाद्यं प्रमाणं परमाणुसंज्ञम् । *Cf.* also त्रसरेणुस्तु विज्ञेयः त्रिंशता परमाणुभिः)

c4.s2.59

¹ Curiously enough, this is fairly comparable (in order of magnitude) with the three latest determinations of the size of the hydrogen atom!

c4.s2.60

The magnitude of a Paramánu is called Párimándalya (पारिमाण्डल्य) in the Nyáya-Vaiseshika, the name suggesting that the Paramánus were conceived to be spherical in shape. The Nyáya-Vaisesnika calls a Paramánu a mere point with infinitesimal dimensions, *i.e.* less than any assignable fraction of any finite quantum; but in the Sánkhya-Pátañjala, a Paramánu, though indefinitely small, had still assignable dimensions, being divisible into Tanmátras, which were themselves integrations of Bhútádi. The diameter of a spherical Paramánu must have been conceived to be less than 3.2⁻²⁰ of an inch (*i.e.* less than the conventional Paramánu with which linear measures begin), and the volume of a Paramánu would, therefore, in accordance with Bháskara's formula, be smaller than 4/6.π.3³.2⁻⁶³ or π.3².~2⁻⁶¹ of a cubic inch, where π = 3927/1250. The Tanmátras were conceived as smaller still.

c4.s2.61

That these were conventional measures arbitrarily assumed goes without question, for of course the Hindus had no physical data for a mathematical calculation of these minute quantities. A Válágra (hair-tip, or finest filament of hair), for example, is taken to be 3.2⁻¹⁴ of an inch thick, *i.e.* less than one-five-thousandth fraction of an inch in thickness; and a fibril of the networks of Dhamaní or Nádí (nerve) that supply the pores of the skin (papillæ? मुखानि रोमकूप-प्रतिबद्धानि, Susruta) was supposed to be about a thousandth part of the finest hair in thickness, or 1/125 of the *minimum visibile*, and, therefore, about 3.10⁻³~2⁻¹⁴ of an inch thick (*cf.* सूक्ष्मनाड़ीप्रचारतः रोम्नः सहस्रभागेनतुल्यासु प्रचरति, Pañchadasí); but it is evident that these measures were arbitrarily fixed upon, instead of being arrived at by calculation or actual measurement. Indeed, Charaka expressly states that the number of Śirás and Dhamanís in the body (three million fifty-six thousand nine hundred) is only a conjectural estimate (अनिर्देश्यमतः परं तर्क्यमेव—Śárírasthána, Chap. VII.).

c4.s2.62

My account of the chemistry of the Sánkhya-Pátanjala, and of the affiliated Yoga and medical schools, has anticipated in several points the views of the Vedánta and the Nyáya-Vaiseshika. The chemical facts, processes, and apparatus are indeed common to all the schools. In the following account of the chemistry of the schools other than the Sánkhya-Pátanjala, I will confine myself to the theory of the subject, and even of this I will attempt only the briefest outline.

Linked texts (20)