CREAM OF TARTAR Is obtained by refining the argol, (which see) found in the juice of grapes. It has an acid, cooling taste and is used in the preparation of summer drinks and as an aid in raising bread and cakes. It is almost universally largely adulterated, being sometimes not more than 3 or pure cream of tartar. Most of the articles used to adulterate it being insoluble earths, it can be tested by boiling it in water 80 times its own bulk ; if any sediment remains it is not pure. Its sale by gro cers is much decreased by the very general nse of baking powders.
Of late years the supply of foreign cream of tartar has consid erably decreased owing to the very marked reduction of the wine crop, and tartar can only form to a paying extent in barrels which are left undisturbed for a period of years. There are usually from one to three inches of dark grounds found at the bottom of full barrels of new wine after they have stood long enough to settle, and about 25 per cent of tartar is naturally pre cipitated with these particles. After a certain time the dregs are removed in a cake, dried, and broken up till they are about the size of common sand and of a pinkish tinge, like the "tailings" of a Nevada quartz mill. These dregs are sold to tartar manufac
turers for about five dollars a bushel. They are put into huge vats of hot water and cooked for about two hours, when they are run off into shallow receivers around which the crystals soon begin to form in a thick mass. As the water always holds a cer tain quantity of the tartar is solution, it is never allowed to escape, but is used over again in the boilers and settlers, thereby prevent ing a loss which must recur as frequently as the water was drain ed off, and which wonld largely diminish the profits of the busi ness. Tartar made from wine that has been cleared with plaster is richest in tartaric acid, while that formed in wine that is clear ed with eggs is richest in cream tartar. The tartar takes a tinge of pink or cream, as the wine in which it forms is red or white.