Chalk, Crete, is a white earth, abounding in Britain, France, Norway, and other parts of Eu-rope, which is said to have been anciently dug chiefly in the island of Crete, whence it has received its name.

This substance is found most plentifully in the county of Kent, in England, on the sides of hills, which the workmen undermine to a certain depth : they then dig a trench at the top, as far distant from the edge as the mining ex-tends at the bottom ; then fill the trench with water, which soaks through during the night, when the whole mass falls down. In Other parts of the kingdom, it generally lies much deeper in the ground.

Chalk is of two kinds : hard. dry and firm, or soft and unctu-ous. The former sort is the best for burning into lime; but the latter furnishes the best manure for lands. Both these species, however, are an excellent manure for sandy sods, as they fill up the interstices, or pores, and give the. land a degree of consistence, which adapts it for the purposes of vegetation, and totally exterminates that pernicious weed, the corn marygold, or yellow oxeye Chrysanthemum segetum L. which abounds particularly in sandy soils. It has a very different effect on clayey ground ; for, so far from rendering it more compact (which is too much so already), it insinuates itself into the small pores ; and, by raising a fer-mentation, exposes the clay more to the operations of the frost, rain, sun, and air ; by which means its too coherent particles are loosened, and it is reduced to a state of pulverization.

It is, however, a circumstance worthy of remark, that, although the Kentish chalk agrees extreme-ly well with other clayey soils, yet, when laid on those lands in Kent, situated near the pits, it by no means answers the expectations of the farmer. This is probably owing to the Kentish clays partaking in some degree of the nature of chalk, which, therefore, has not so good an efffect in Kent, as id other parts of England; the quality of the manure being nearly congenial with the soil. It also deserves to be noticed, that chalk, however excellent it may be in itself, when mixed with dung or any other manure, is so far from ameliorating the soil, that crops to he raised from it, receive no benefit what-ever, and it totally loses its invigo-rating qualities.

Chalk easily imbibes water: hence masses of it are employed for drying precipitates, lakes, earthy powders that have been levigated with water, and other moist preparations. Its domestic uses for cleaning and polishing metallic or glass utensils, are well known ; for which purposes it is pounded, and by washing it, clear-ed from whatever gritty particles it may contain, and then called whiting. It is also of considerable service on shin-board, when mix-ed in the proportion of half an ounce to a gallon of distilled seawater, which may Bills be sweet-ened, ami kept perfectly fresh.

In medicine, chalk is reputed to be one of the most useful absorbents, and in this light only, deserves notice; as the astringent virtues, which some have attributed to it, are utterly unfounded. in so far as the earth is saturated with acid, in which combination it forms a saline concrete, that is manifest -ly astringent. Several years since, a person at Edinburgh pretended to have discovered a specific for curing every kind of those erythe-matous or inflammatory eruptions, which often attend the chronic or the rose, on the legs, merely by applying powdered chalk to the parts affected : and though we have had no experience of this remedy, it does not appear, to us, as proper and safe as hot flour, the good effects of which, On such occasions, we have frequently witnessed.

Chalk Lands are thus deno-minated, from their consisting principally of chalk, with a thin layer of mould, or soil over it: They are well calcinated for the growth of barley and wheat, and especially of oats, which will thrive on any kind of chalky land, however indifferent. It naturally small species of vetch, smooth podded tare, or tare, Ervum tetrasperum, L.

together with poppies, May-weed, etc. - Sainfoin, and hop-clover, will also succeed on these lands; and, where they are of the better sort, the hare's-foot trefoil. Triflo-ed with particles of iron or steel. Chalybeate medicines operate,

1ike other preparations of iron, both as aperients and as astringents, the only difference in degree. supposed to fer according to the nature of the acid united with the metal : thus, vegetable acids impart to them a detergent and aperient virtue ; - when combined with the vitriolic acid, they operate on the first pas-sages as powerful aperients ; the nitrous acid renders them very styptic, and the muriatic produces the same effect, in the highest de-gree.

The use of chalybeates has, oc-casionally, been attended with great success, when united with cathartics, especially in cases of chlorosis, pains of the stomach, and palpitations of the heart; but we think it our duty to caution the reader against resorting indiscriminately to remedies which are extremely precarious for plethoric, or very irritable constitutions, and sometimes productive of dangerous effects. Hence females, in parti-cular, ought never to take them, without proper advice.