An examination of large quantities of Tibetan data for a project entitled 'Alchemy and Alchemic Medicines of Tibet revealed that ancient Tibetan terminology for and classification of inorganic salts have much in common with modern chemistry. This is particularly true of research conducted by Tendzin Phuntso (born in 1672 in Gongjo County, Chamdo, Tibet)' and his representative work, "gso rig gcesb dus rin chen phreng ba bzugs so". This work summarizes Tibetan recognition of inorganic salts in chemistry over the course of 1,000 years or more, and is of great significance in the world history of science and technolgy.

1. Terminology and classification of salts.

Demar Tendzin Phuntso (TP) divides salts into two classes: natural and artificial. Natural salts encompass 21 varieties: salamoniacum, sallucidum, lake salt, halitum, violaceum, iodine salt, nitrum, borax, sal, halitum salt, humus nitrosus, nitrum, cliff salt, plain salt, trona; cinnamomum cassia, mirabilitum, and alum (white, green, yellow, and black). Artificial salts comprise salluci dum;halitum; sales alcalinoorum; horn salt; ash salt; hydrogyrum salt; black-ear salt; nitrum; chalcanthitum, and seven calcinated salts, totaling 16. There are, therefore, 37 kinds of salt. But, Tendzin Phuntso postulated that there are also overlapping salts in the two groups that can be obtained from nature or by artificial methods, and that these 27 hybirds should also be termed "salt". In both the Lunar King of Medical Investigation, the earliest extant Tibetan classic, and Rgyud bzhi3, many salty medicines are grouped under the same category, including salamoniacum, sul, horn salt, black salt, red salt, iodine salt, and cinamomum, all bearing the name "tsha" (salt). The technical section of the Buddhist Canon Tanjur contains a translation of a paper on alchemy by Rinchen- Pal, a Tibetan translation master, entitled Dngul Chu Grub ba'iBstan bcos, in which borax, sea salt, humus nitrosus, nitrum, and cooking salt are mentioned, mostly bearing the term "tsha" (salt). As these salty materials have a high frequency of application, they are categorized under the "salt" group.

The Tibetan people applied and recognized many kinds of salt before a Tibetan writing system had been established, and hence created the term "tsha," which includes soluble salts, such as copper sulphate, potassium nitrate, and ammonium chloride; and neutral salts, such as sodium bicarbonate and potassium carbonate. The hydrogyrum salt Tendzin Phuntso mentions is a mixture of the nonsoluble salt mercuric sulphide, borax, nitrum, and mercury.

Early medical alchemists of inland China also recognized and applied salts through alchemical and medical practices. They gave the name "salt" to salty substances such as rock salt, strong salt, cold salt, white salt, green salt and black salt, all of which refer to sodium chloride; minority salt (yi salt) refers to ammonium chloride; and halogen salt to sodium carbonate.5 There are also soluble salts bearing the name "nitre", including simple nitre, nitre stone, sweet nitre,arista nitre, tooth nitre, wate nitre, and fire nitre, actually referring to potassium nitrate, sodium sulphate, and magnesium sulphate.6 The inland Chinese studies of salt, compared with those recorded in ancient Tibetan literature, are less extensively and systematically classified.

Tibetans included non-neutral salts under the category of salts much earlier than did the Europeans. In the Western world, it was not until 1754 that chunistry teacher G.F. Rouelle (1703-1770), to Lavoisier:

"called alkalies base, thus expanding the scope of the concept of salt, which had hitherto only included neutral and soluble compounds."7 The European discovery was made almost exactly one thousand years later than the findings recorded in the Rgyudgzhf which was written in 754.

If Tendzin Phuntso's hydrogyrum is also regarded as non soluble salt, this is also a much earlier classification of non soluble salts placed under the category of salt than was ever made in Europe. Since it was so early on in history that the Tibetans recognized inorganic salt, they had no modern theoretical framework to analyze salt. The early Tibetan experimenters recognized salt only by its salty taste and its medicinal effect, and this inevitably lead to confusion. This method also led to the inclusion under the salt category of other substances, such as cinnamum bark. In the "Blue Lapis Lazuli", it is stated: "Cinnamum barks is pugent, sweet, astringent, and salty to taste." Hence, the bark was classified as a salt. Under current classifications, cinnamum bark is not a salt component.

2. On sal ammonicum and nitrum

In the 9th and loth centuries AD, an Arab alchemist discovered and applied sal ammoniacum. This discovery, like the Tibetan finding, occurred much earlier than in Europe. However, the "Rgya tsha" mentioned in "The Lunar King of Medical Investigation" (Soma Ratsa), which is said to relate to inland Chinese written medical works that were taken to Tibet by Princess Wencheng more than 1,000 years ago, also refers to sal ammoniacum. In the Tibetan language, "Rgya" refers to the inland Han nationality. Does this mean, then, that"Rgya-tsha" is "Han-salt"? This needs further investigation. Sal ammoniacum is not commonly referred to, is absent from Ge Hong's "Baopuzi",and is only seen in volume 11 of the Tang "Herbology" (compiled in 659), where it states:

"Sal ammoniacum oftens gold and silver, and can be used as a medicine to induce for sweating."As regards nitrum, the first known reference to it was seen in the "Lunar King of Medical Investigation".

"Blue Lapis Lazuli"9 states that:

"Nitrum, also called 'melting agent', melts all stones".

"Pearl Herbology" 10 states that:

"Nitrum eliminates lithasis and'destroys lumps.

When burnt, it expands and bursts with a cracking sound in the form of ice. After washing and processing, it forms fine crystal needles."

In his "Selected Medical Works," Tendzin Phuntso points out:

"There are three kinds of Nitrum: superior, intermediate, and inferior. However, all three burst with a cracking sound when burnt."Tendzin Phuntso made earful observations and witnessed the following reaction:

The strong oxidized agent potassium nitrate decomposes and liberates oxygen, exacerbating the burning reaction. In Europe, it was not until late i8th century that C.W Scheele discovered and proved the presence of oxygen. It was much later that any European mentioned nitrum. J. Needham, an English scholar, said: "It is the lack of nitrum that delays the progress of chemistry in Europe." "Although there is reference to the application of fire by Greeks in The Bible, no manuscript materials on nitrum are recorded as having been found before the 12th century in Europe.12 For a period of 2,000 years, the search for the chemical constituents of "nitrum" persisted until after the time of Li Shizhen (1518-15:93), a Ming Dynasty medical scientist. The analysis and identification of the "nitrum in" The 46 Kinds of Tang Dynasty Medicine, preserved in the Shiosoyin in Japan, controversially analyzed and identified nitrum as being megnesium sulfate with 7 molecules of waterI3. This shocked the provinces of chemistry and medicine. The "Ce-tsha"in Tibetan pharmacy is actually nitrum. In The Annals of Tibetan Material Medicine 14, the entry "Ce-tsha"says: "The chemical constituent of Ce-tsha, applied by Traditional Tibetan Hospital in Lhasa, is potassium nitrate."

Hence, it can be seen that the nitrium mentioned in Tibetan medical and pharmacological works is actually potassium nitrate. Strangely, the "Ce-tsha"entry in the Great Tibetan-Chinese Dictionary says that "All arista nitrum, fire nitrum and nitrum stone are mineral stones of sodium sulfate." Whether or not it is composed of different chemical constituents due to products that come from different locations is still open to further investigation.

3. Preparation of artificial salts

There are 16 artificial salts according to Tendzin Phuntso. It is interesting to note the production methods he mentions. Here are two examples:

1) Preparation of blue vitriol: "Sal ammoniacum 10 potassium; potassium (or magnesium), alum, each 5 parts; borax i part; fine powder of good copper fragments 10 parts. Immerse in nice wine and defatted cow's milk. Put in a bowl after baking, and cover with green and moistened Dracocephalum tanguticum. Let ferment for three whole days and then dry in the shade. If there are still insoluble precipatates, repeat the above process, until sky blue salty crystals appear." The process can be shown by the following reaction formulae: NH4CI(sal ammoniacum)-* NH3+HCL 2Cu(copper)+HCi+02(air) —? 2CuCL2+H20 (in the presence of air, copper can be dissolved in sulfuric acid slowly) CU-SO--4—CUS04 (SO 4is derived from alum) Nowadays, copper sulfate is prepared by the action of sulfuric acid on copper fragments or copper oxide.

Yet, Tendzin Phuntso acquired alum through the above procedures without the availability of sulfuric acid.

2) Isolation and Purification of nitrum "Collect all the materials after discarding mud and other impurities. Add seven times the amount of water and boil. Let stand for one night and filter the next morning. If there is still some odour in the residues, add water and filter as before. The filtrate may be white or yellow in color owing to different sources of raw material. In any event, all precipitates should be discarded. If the filtrate is turbid, wash with cool water.

If isolation is impossible, add cypress ash, superior actinolite or a mixture of wine and cow's milk. Discard the precipitates. Collect the filtrate, which is like defatted milk, and let stand for a whole day and night. Obtain the needle or ice crystal. Boil the remaining fluid. Repeat the process to obtain more crystals, which can then be differentiated into three types. The superior crystal is white and needle-shaped; the brown powder form is intermediate; and the baked barley-flour form is inferior."

This process is similar to the current procedure for obtaining sodium nitrum (with Chilian nitrum as raw material), i.e. water extraction, filtration, concentration, and crystallization. However, Tendzin Phuntso used cypress ash (mainly potsium carbonate), superior actinolite (calcium or magnesium silicate), and coagulants like cow's milk and wine, causing coagulation by adding electrolytes from inorganic salts and opposite electric charges from particles of neutral colloids, or by adding milk to the salt solution, so as to analyze the salts in the proteins, with ensuing agglutination and precipitation.