URNSOL, a dye-stuff manufactured in Holland, the preparation of which was long kept a profound secret. In order to mislead foreigners, the Dutch pretended that turnsol was made from rags dyed with the juice of the sun-flower (Helianthus), from which it obtained its name. Since the late revolution, however, in Holland, the true method employed by the Dutch for preparing this colour has been discovered, and the process is as follows:—That kind of lichen called orchil (Lichen-Rocella. See that article in this Suppl.), or, when that cannot be procured, the large oak-moss, after being dried and cleaned, is reduced to powder, and by means of a kind of oil-press the powder is forced thro' a brass sieve, the holes of which are small. The sifted powder is then thrown into a trough and mixed with an alkali called vetar, which is nothing else than the ashes
Turpentine. ashes of wine lees, in the proportion of half a pound of ashes to one pound of powder. This mixture is moistened with a little human urine, for that of other animals contains less ammonia, by which a fermentation is produced; and the moistness is still kept up by the addition of more urine. As soon as the mixture assumes a red colour, it is poured into another trough; is again moistened with urine, and then stirred round in order that the fermentation may be renewed. In the course of a few days it acquires a bluish colour, and is then carefully mixed with a third part of very pure pulverised potash; after which the mixture is put into wooden pails, three feet in height, and about half a foot broad. When the third fermentation takes place, and the paste has acquired a considerably dark blue colour, it is mixed with chalk or pulverised marble, and stirred well round that the whole may be completely united. This last substance gives the colour no higher quality, and is intended merely to add to the weight. The blue, prepared in this manner, is poured into oblong square iron moulds; and the cakes, when formed, are placed upon fir boards on an airy floor in order to dry, after which they are packed up for sale.