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Here the author of Bogar karpam gives a metallurgical process for the synthesis of a silver-coloured alloy, which he calls "China Silver". To begin with, we will see the details of the process and later we will compare the percentage composition of the alloy to the other silvery-white alloys known to the Europeans under the names "China silver" and "Chinese silver". Sloka 167 Vellerukku (Calotropis Giganta albiflora) Obtain Vellerukku flowers and extract the juice from them. Give Surukku (i.e., heat in an iron laddle and pour hot) to Pashanam. (Gandhapashana, i.e. sulphur) with the milky sap drawn from the Vellerukku plant. Follow it with the Surukku with the flower juice. Grind the seeds of the plant to a paste. Encase the Pashanam with the paste. Grind the root of the plant with the extract obtained from the crushed, withered leaves of the plant. Seal Sloka 168 Make a crucible out of a well-ground root. Place the encased Pashanam inside it. the mouth of the crucible with clay. Calcine 44 the Pashanam in a "Gajaputam" (i.e. the furnace of a shape of the elephant's head). Add equal weight of tin to it. Tin will melt and will be rendered brittle. Sloka 169 Add to the tin equal to its weight of iron filings, karam (borax) and melt it. Add silver equal to the weight of the combination. Empty the molten mass in a stone mortor and allow it to cool. Grind it thoroughly. Add again mercury, karam (borax) and arsenic. Triturate the mixture, moisten with milk and grind it again to paste. 44 To Calcine To convert into calx by heat or oxidise by heat.

125 Sloka 170 Press the paste into pellets and dry them in sun. Encase the pellets in Puniru (a kind of soil). Calcine them in kamalaththi (low heat) for four Jamams (one Jamam is two hours). You will obtain a potential kalangu 45 from this process. Added to copper in the proportion one to fifty, it will turn copper into silver. It is not an alloy but pure China Silver. This is the only place where we come across a reference to China. The one obtained in the above process is an alloy of tin, iron, copper, silver, mercury and arsenic. The final product must be silvery-white and lustrous since the author writes, "This is not an alloy but Pure China Silver." Silver, when diluted with relatively large amounts of other base metals, still maintains its colour and lustre. When copper is added to silver in large quantities, the resulting alloy is well known to be silvery-white. It seems the author of Bogar karpam is using this property of silver in his "China Silver" method. One such silver-coloured alloy was imported from China to Europe in the seventeenth century. It was used 46 45. Kalangu A preparation of the above kind, which when mixed in small quantities to large quantity of base metal, converts it into noble metals. 46. Needham, Joseph (1), Vol. 5, Pt. II, p. 226.

126 in making dinner-table articles and looked very much like pure silver. This was named Paktong or Bai-tong (meaning white copper in Chinese). Its exact nature was not known until the eighteenth century. Von Engerstrom reported his analysis of the Paktong ingot in 1776. It contained equal percentages of copper and zinc with 15.6 percent of Nickel. Also two of the Nickel-containing alloys are listed in modern European manuals as "China silver" and "Chinese silver". They contain only two percent of the precious metal and one of the alloys contains some cobalt and the other 19.5 percent tin. Their percentage composition is given below: Percentages Silver Copper Tin Zinc Nickel Cobalt of Ag Cu Sn Zn Ni Co China Silver 2 65 19.5 13.0 Chinese Silver 2 58 17.5 11.5 11 The origin of the above names is not known for lack of evidence. (But one thing is beyond doubt: that the names and methods of preparation of the above alloys must have originated in China, since they have acquired these names.) Thus we may surmise that ideas regarding silver-coloured alloys were transmitted from China to other

127 Asian countries like India and later to Persia and Europe (in the seventeenth century AD). The Persian silvercoloured alloy, used for coins, was similar to the above ones, but contained no nickel. The "China Silver" of Bogar is then very much like the Persian coin-metal, only that it contained no cobalt or zinc, but iron instead. Dan-yang transmutation of copper is much talked of in ancient Chinese texts, where a silvery alloy was made from Dan-yang (a place-name in China) copper by adding refined arsenical powder. Again, Bogar's China Silver was not by the Dan-yang method since it did contain some precious metal (about two percent) where the Dan-yang transmutation does not involve the adding of any silver. Bogar's method, in short, is as given below: Tin is melted in a crucible with certain sulphur which is previously treated with the juice of the plant Vellerukku (Calitropis Giganta Albiflora). Iron filings and Borax are added to this tin and then it is melted. Silver equal to the weight of the combination is added to it. The molten mass is allowed to cool and is then ground in a stone mortor. Afterwards mercury, borax and arsenic are added to it, and powdered thoroughly. The mixture is moistened with milk and ground to form a paste. The paste is pressed into pellets and they are dried in the sun. These pellets are encased in a certain soil and calcined

128 for four periods. The resulting powder is added to copper in the proportion one to fifty, turning copper into silver. The resulting alloy must have had about ninetyeight percent of copper and less than one percent of iron, tin and silver each. From the compositions of the various silver-coloured alloys given above, it is evident that Bogar's China silver was not exactly like any one of them. It seems that these ideas of making silver alloys by diluting silver with large percentages of copper reached India from China, many centuries before they reached Europe. Bogar's China silver was essentially similar to European China Silver and Chinese Silver since they all contain about one to two percent of silver and large amounts of copper. Inclusion of this method in "Bogar karpam" strengthens the traditional belief that Bogar was a Chinese alchemist and indicates the transmission of alchemical ideas from China to India in the early medieval period. Bogar's practical way of writing alchemy, unlike Wei Bo-yang's or Ge Hong's, and inclusion of harmful ingredients in edible elixir methods, together suggest that Bogar's period must be between the fourth and the ninth centuries AD. This style of writing, according to Needham, became prevalent among Chinese alchemist writers

129 after Ge Hong and is observed in Sun Si-miao's writings (i.e., the seventh century AD). Needham writes, 47 Chinese alchemy seems in a way to have reached its peak of development between the time of Ge Hong early in the +4 th century and that of Mei Biao at the beginning of the +9 th. This can be seen in the lucid style of many of the alchemical writings of this period (a great departure from the abstruse language used by Wei Bo-yang), in the adventurous experimentation with ever greater number of inorganic substances for elixir recipes and in the development of alchemical theory. The majority of the most important proto-chemical writings we now possess belong to this period. From the +9 th century onwards there was a tendency to revert to the gnomic and theoretical style, a marked decrease in the number of substances used in elixirs, and a growing interest in substances of plant and animal origin. In this way, the comparison of the chemistry of Bogar karpam with early medieval Chinese methods reveals similarities between the two. The chief reaction in a second century Chinese alchemist's text (Wei Bo-yang's can-tong-qi) is repeatedly described by Bogar for making an elixir. Again the elixir-formulae of Bogar are very similar to those given by Ge Hong, a fourth century Chinese alchemist. Moreover, the recipe given by the author of Bogar karpam for China silver parallels the one which was known to the Europeans in later centuries. Hence it is apparent that the ideas of making silvery 47. 'Needham, Joseph, Vol. 5, Pt. III, p. 182; also see FN. 34 in the chapter on Alchemy in China.

alloys reached India from China many centuries before they reached Europe. 130