MADDER.

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material is removed from the bags. It is transported to the drying-stove, andafter having become quite dry it is reduced to powder by mill-stones similar tothose used for the grinding of madder. This millwork is very different fromthat used for grinding grain, and more resembles that in use for grindingcoprolites. The ground-up material is packed in casks, commonly linedwith stout paper inside, while the seams between the staves are covered withpitch.

Bloom of madder is also prepared by mixing the madder with from eight toten times its weight of river water, and leaving this mixture for from two tofour days at rest, at a temperature of from 18 0 to 25 0 . When the alcoholic fer-mentation which sets in is complete the liquid is run off, and the operation isfinished as just mentioned. When the alcoholic fermentation takes place inthe presence of a large quantity of water, the colouring principles of themadder do not suffer any change, and are not decreased in their tin&orialvalue ; but when either the pasty mass—above referred to as left in the filtertank—or the pressed cake is suffered to undergo fermentation, the colouringprinciples are sometimes altered and somewhat deteriorated, and on thataccount, and in consequence of the irregularity of the fermenting processunder these conditions, it is no longer used in the Avignon district. 100 kilos,of madder jyield from 55 to 60 kilos, of bloom of madder, according to thenature of the raw material. Generally speaking, the better qualities of madderyield a less weight than the lower qualities, but the tin&orial value is verysuperior. The quantity of madder annually converted into bloom of madderin the Avignon district amounts to 4,000,000 kilos.

The manufacture of alcohol from madder is a profitable business : 100 kilos,of madder yield from 7 to 10 litres of alcohol, at 87 per cent; the superiorkinds of madder yield a larger quantity than the lower. This alcohol, in theraw state, is unfit for drinking. Its taste is very disagreeable, and its smellmuch like that of wood-spirit. It is employed for the preparation of varnishand ether. M. Schutzenberger states, probably upon the authority of some ofthe distillers resident in the Avignon district (it should be mentioned that someof the manufacturers of fleur de garance are distillers at the same time, butmany sell the fermented or fermentable liquid, or raw spirit, to distillers), thatthe alcohol from madder can be rendered quite sweet by contact with poroussubstances—especially pumice-stone and wood-charcoal—and re-distillation,and then become as good as rectified beet-root alcohol. There is establishedat Sorgue, near Avignon, an extensive distillery, wherein the largest portionof the alcohol obtained in that district is rectified and purified to such an extentas to compete successfully with the alcohol obtained from wine. Accordingto the opinion of some chemists * the peculiar odour and taste of the alcohol

* The researches of Gunning, of Amsterdam, have proved that the odour of the alcoholobtained from the washing-liquors of garancin and fleur de garance is due (in the case, at least,of Zealand madder) to acetic ether and aldehyde. The raw madder-spirit is an excellentsource for aldehyde-ammonia. The preparation is as follows :—From 20 to 30 litres of theimpure spirit are placed in a still provided with a long copper worm, and heated to 6o° or 70°C., while at the same time a rapid current of air or carbonic acid is passed over the liquid.The distillation is continued until the distillate ceases to give a darkish colouration withcaustic potash-lye. To the distillate is added twice its bulk of water, powdered hydrate ofbaryta being stirred in till a decided alkaline reaction is perceived, in order to decompose theacetic ether. The excess of baryta is removed with carbonic acid. Aldehyde is afterwards