Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/61

Rh and viscera, feebleness, slow-fevers, hectics, rickets, and other lingering and fatal diseases.'

To discover such unlawful practices, requires no chemical skill: on macerating a small piece of the crumb of new-baked bread in cold water, sufficient to dissolve it, the taste of the latter, if alum has been used by the baker, will acquire a sweetish astringency. Another method of detecting this adulteration, consists in thrusting a heated knife into a loaf, before it has grown cold: and if it be free from that ingredient, scarce any alteration will be visible on the blade; but, in the contrary case, its surface, after being allowed to cool, will appear slightly covered with an aluminous incrustation. This method, we understand, is generally preferred in the experiments made by country-justices. It deserves, however, to be remarked, that a very small proportion of alum, such as a few grains to a quartern-loaf, cannot be productive of any serious effects. In relaxed and scorbutic habits, or to those persons who are troubled with flatulency, bilious colic, and jaundice, such medicated bread may be conducive to the recovery of health; while in others, of a plethoric constitution, and a rigid fibre, it cannot fail to aggravate their complaints. In short, such addition to a common article of subsistence is, to say the least of it, highly improper, and ought not to be intrusted to the hands of a mechanic.

One of the most important purposes, to which this concrete salt may be readily applied, is that of purifying and sweetening water that has become fetid and unfit for use. On long voyages, or at a distance from clear rivers and wells, each gallon requires, according to its impurity, only from five to ten grains of calcined alum, and double or triple that proportion of powdered charcoal, in order to render the most offensive water perfectly sweet and pellucid: both ingredients, however, ought to be preserved in close vessels, or otherwise their efficacy will be considerably diminished.

Alum has also been tried in the boiling of salt, to render it of a firm consistence, but the good which was supposed to be derived from it, is now solely attributed to the effects of the slow and gentle heat, so that in this process it has of late been discontinued.

The manufacture of alum was first invented in the year 1608, and greatly encouraged in England, by Lord and other Gentlemen of the county of York. King the 1st assumed a monopoly of that article, and prohibited its importation.  Alyssum sativum, L. See.  Amaranthus Blitum, L. See.  Amaurosis. See.  AMBER (Succinum) is a hard, bituminous substance, possessing a subacid resinous taste, and a fragrant aromatic smell. It is the production of many countries, but the best sort is that which is found in various parts of England, especially in the clay and gravel-pits between Tyburn and Kensington, as well as behind St. George's hospital, near Hyde-Park Corner, where fine specimens of this concrete are occasionally discovered. Prussia possesses it in great abundance, and the king derives from this article alone an annual revenue of