How Lake Van Bleaches Its Children

A little over a year ago we stood on the shore of Lake Van and watched the sun go down into the water. The subject that evening was fish, flamingos and cats. I had overlooked the most obvious constituency of all: people.

Ankara’s English-language mouthpiece Daily Sabah has now reported something the shore itself stopped finding remarkable generations ago. Every September the local children come back from the holidays in a different colour. They are, as a rule, emphatically dark—not like our stretch of Thrace, where Circassian and Bulgarian settlers deposited a good deal of pale fire. By the first week of term half the class has gone a shade that in London would cost eighty pounds and an afternoon.

A fisherman explains it in the tone other people reserve for the turning of the seasons: the autumn child is unrecognisable by spring, the hair having grown out and been cut off, and there he is again, black as a crow. Teachers newly posted in from other provinces spend their first term reproachfully asking the children to stop dyeing their hair. Explanations follow.

The secret is the water, of course. Lake Van has no outlet—the lava of Nemrut saw to that, and tectonics did the rest—so everything the rivers carry in stays in, and the only way out is upward, as vapour. Several hundred thousand years of that arrangement produce soda. The alkali lifts the scales of the hair shaft; the sun, at 1,648 metres, does the actual bleaching, breaking the melanin down by oxidation. A salon achieves the same result with ammonia to open the cuticle and peroxide to do the damage; Van supplies the first free of charge and appoints the sun to the second post, with a view of Akdamar thrown in. A trader in Gevaş adds the technical footnote: rinse in fresh water straight after swimming and nothing happens at all. Neglect to, and a month is ample.

A solution, etymologically speaking

Alkali came into Europe from Arabic اَلْقِلْي, al-qilī, “the ashes”—not ashes in general, but the ash of the saltwort, the succulent that thrives on salt ground and served both as a vegetable requiring no further seasoning and as a source of lye. The plant carries the word to this day: Linnaeus called it Salsola kali, the Spanish burned it as barilla, and the English, with characteristic literalism, named it after what it was for—saltwort for the salt, glasswort for the glass.

Here linguistics has to be mixed with a little chemistry (stirred, not shaken). While the saltwort grows it draws up salts of organic acids and stores them. Burn it, and the organic part goes off as smoke while the metal stays behind in the ash as a carbonate. In saltwort and its relatives on the salt flats that metal is predominantly sodium, so the ash yields sodium carbonate, Na₂CO₃—soda. Burn wood instead—birch, beech—and you get potassium carbonate, K₂CO₃, that is, potash. Early modern chemists filed the two accordingly: alkali minerale, the mineral sort, out of the salt-flat herbs, and alkali vegetabile, the vegetable sort, out of the forest. Add slaked lime, Ca(OH)₂, to a solution of potash and causticisation gives you chalk and potassium hydroxide, which is a caustic alkali in earnest; boil it down, combine it with fat, and you have soap. The raw ash, meanwhile, went straight to the glasshouse without any causticisation at all, where it lowered the melting point of quartz sand.

English, incidentally, did not coin potash out of pot and ash; it borrowed the compound wholesale from Dutch potaschen in the sixteenth century and translated it word for word, which is the same thing done more politely. And beside the Arabic loanword sits the native one: lye, Old English lēag, from the Proto-Indo-European root *lewh₃-, “to wash”—the root that also gave us lather, lotion, lavatory and deluge, and gave Scandinavian its lördag, Saturday, literally washing-day. Arabic named the substance after the ash it came from; Germanic named it after the laundry. The periodic table sided with the ash.

Which brings us to the awkward business of element 19. Kalium is simply alkali with the definite article removed, and Martin Klaproth had proposed kali as a name for the metal as early as 1797, before anyone had laid eyes on it. Humphry Davy, who isolated it by electrolysis in 1807, preferred potassium, after the potash he had pulled it out of. Two years later Ludwig Wilhelm Gilbert, translating Davy for the Annalen der Physik, added a footnote suggesting that German would do better with Kalium and Natronium; Berzelius adopted the Latin forms for his notation in 1814. The result is that an English chemist says “potassium” and writes K—a compromise nobody actually negotiated, in which the Arabic word won the symbol and the Dutch one won the name.

The lake as chemical works

For several thousand years, obtaining something to wash with meant growing a plant, burning it, and pouring water over the ashes. Lake Van dispenses with the first two steps and delivers the finished article by gravity, in a quantity variously estimated at 576 to 607 cubic kilometres. The villages along the shore carried their washing down to it for centuries and saved on soap. A washing machine is harder to carry, and would not, I suspect, survive the water for long—but one can still economise on the hairdresser. The blond is guaranteed; the shade is negotiable.

So if you meet a black-haired boy on the shore of Van in May, take the long view. It is a temporary condition. The lake already has him in the wash.