Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/130

106&#93; io6] ARR starch-plant, and is likewise used by the Indians to extract the poison communicated by their arrows. Dr. Wright, of Jamaica, ap- pear* to be the first who informed us that a decoction of the fresh roots makes an excellent ptisan in acute diseases. From an ingeni- ous pamphlet published in JQQ, by Mr. T. Ryoer, of Oxford- street, we farther learn, that one of his ".Vest Indian patients employed it as an article of diet, and since that period it has been very gene- rally used in families. The arrow-root powder unques- tionably yields a larger proportion of nutritive mucilage than any Eu- ropean vegetable, if we except the Salep-rooi : hence a single table- spoonful of either, makes a pint of strong and nourishing jelly, which affords a very proper food in acute diseases as well as in all those complaints where animal food must be abstained from. It is there- fore to be regretted, that we cannot easily obtain this powder in a pure state, without paying the extrava- gant price of from five to ten shil- lings per pound ; for in those shops where it is offered to sale at an inferior price of two or three shillings the pound, we have found by experience, that it is consider- ably adulterated. Mr. Ryder, before mentioned, has justly recommended the cul- ture of this root to the West Indian Planters, and the new African Co- lonists, as an object, of commerce, and the most eligible, substitute for starch made of wheat : 1. Be- cause it would save annually 6(5,000 quarters of that valuable grain, in Great Britain alone, where the average quantum of starch made in the years Ijg?,, 1794, and 1/95, amounted to S millions of gouuds ARS weight, allowing one hundred and twenty pounds per quarter ; — 2. As the wholesale price of the arrow- root was, in 1/06, fifteen pence a pound, and as one pound of its starch is equal to two pound and a half prepared from wheat, its in- trinsic value would, by this com- putation, not exceed «,r-pence per pound : whereas the average price of starch in England for seven years (from 1/80 to 1705) may be stated at 7j£nopence the pound. 3. As the arrow-root contains more soluble, gelatinous matter, occupying less space, being less enveloped in earthy particles, and affording a purer farina than any other plant, it may be reasonably inferred, that the starch obtained from it must be of the finest quality ; an opinion amply confirmed by three clear- starchers, who were, on this occa- sion, consulted by the Society for the Encouragement of Aits, Manu- factures, and Commerce. ARSENIC, an heavy, opaque, crystalline substance, which, on fracture, resembles sal ammoniac in a concrete state. Most of the metallic ores contain it in greater or less proportion, especially those of copper, tin, bismuth, and the fossil called cobalt, from which last it is extracted in Saxony, by a kind of sublimation. Its true nature is so little known, that che- mists have hesitated whether it ought to be ranked among the salts, or semi-metals ; because it may, by various processes, be made to assume either a saline or metal- lic state. Hence, it has by many been considered as a mineralizing substance, which only tends to combine metals, and to give them a more perfect form. Kay, there are others, who have doubted whe- ther it be a simple bo ly ; and we well