dried spent leaves, and when the ash is deficient, the explanation is that the genuine tea has been more or less replaced by spent or exhausted leaves. But for all practical purposes a complete analysis of tea-ash is not necessary, a determination of the ratio of soluble to insoluble portions of the ash answering the purpose as well. Such a determination is made by boiling the ash several times with a little water, filtering and washing the precipitate in the filter, drying, igniting and weighing it. The weight of the insoluble part of the ash may then be subtracted from the original quantity, in which manner the percentage of soluble and insoluble ash is obtained. Peligot has also pointed out that tea-leaves differ from the leaves of other plants by their extraordinary richness in nitrogen, the percentage averaging 4.37 per cent. in the raw leaf of the former, and ranging from 5.10 to 6.60 per cent. in the dried state. In the preparation of the fresh leaves for market a quantity of juice is expressed from them, the increase of nitrogen in the prepared leaf being accounted for on the supposition that this juice is not as rich in nitrogen as that still remaining in the leaf, and if the prepared leaf be unique in containing this high percentage of nitrogen, it is obvious that a determination of nitrogen in tea may prove useful as a method of identification. IRON AND STEEL FILINGS IN TEA Are best detected by pulverizing a sample of the suspected tea and spreading the powder on a piece of glass or plate, and applying a magnet to the dust. If a quantity of the particles gravitate and adhere to it, the tea is undoubtedly adulterated in this form. While fabrications and sophistications in general may be best exposed by treating an infusion of the leaves with a watery solution of sulphuretted hydrogen or a weak solution of ammonia. Under the first treatment the liquor of pure teas will retain its natural color, but will assume a light-blue tint under the latter. Another simpler method for those who may not have the chemicals or appliances convenient is to place a small quantity of tea-leaves in a wine-glass or goblet, pour on cold water, and stir or shake well for a few minutes. The tea, if pure, will only slightly color the water, but if adulterated, a dark-colored liquor is quickly yielded, which if boiled and let stand until cold will, if spurious, become bitter and almost transparent as it cools, while pure tea under the same conditions assumes a darker color and pleasing flavor. The latter changes arise from the tannin (a natural property in tea) of which artificial tea is entirely devoid and adulterated teas in proportion. Mineral adulterants, however, must be dealt with by the ash-test, which is unerring, spurious leaves by their botanical character and structural marks, deficiency of tannin being invariably an indication of spent or exhausted leaves.