e M k By in those of iron, I ties li is usually dusky, brownish red on the Rtrface; but, when broken, is of .1 fine I I lish iron- fcpangled with glittering specks ; which are in a < irnpi . '.ih that metal. It is also sometimes red, when it usually contains veins of gold. This stfuie, or or^, is divided into three sorts, namelyj the Spanish, the red, and the common emery. The fiiM is found in the gold mines of Peru, and is interspersed with small veins and specks of gold;
hence it is conjectured to be a
kind of ore of that rich metal, and is prohibited to be exported. From the experiments made by natural* i-ts, it appears to be the metal call- ed Platiwa, to which we refer The red emery is discovered in cop- per-mines, chiefly in Denmark and Sweden ; whence a small quantity is imported. The common emery is dug up in great abundance in the island of Guernsey. It is also ob- tained from some iron-mines in England, and is the only sort which is consumed in very considerable quantities by locksmidis, glaziers, lapidaries, masons, cutlers, and others, who employ it for cutting and polishing' glass, marble, and precious stones ; as well as for the polishing and burnishing of articles made of iron and steel. This spe- cies of emery is of a brownish co- lour, inclining to red; is extremely hard, and consequently very diffi- cult to be reduced to powder ; an art which has been discovered in this country, and is effected by means of certain mills, invented for the purpose : when pulverized, it forms a considerable article of ex- portation. This native ore, when fused with lead or iron, possesses S#, vr,— .vol, ii, E U £ [225 the property of hardening those metals. It is also the weight, and heighten the colour of gold. — Ir . no notice r as an internal medicine, or as a dentrificei EMETICS are those medicines which arc either given with a view to discharge the foul or poisoned contents of the stomach, or to vel- licate the coats of that organ, and thus to produce certain changes in other parts of the animal economy, not immediately connected with the process of digestion. With the latter intention, small nauseating doses are generally administered, especially in catarrhal and other diseases of the breast. In this place, however, we shall but briefly enu- merate the cases in which vomiting may be excited with a probability of success; and also, those instances in which this remedy cannot be safely adopted. Emetics may be of great service: 1. Immediately after swallowing narcotic and other poisons (see An- tidotes, vol. i. p. 75) 5 2. For the purpose cf evacuating viscid, bili- ous, and putrid matterSj or undi- gested food from the stomach ; 3. To assist Nature, when there is a spontaneous effort to vomit; 4. To expel substances fallen into and obstructing the passage of the gul- let; 5. To promote the expectora- tion of mucus and purulent matter, collected in the lungs and wind- pipe ; — as well as on many other occasions. On the contrary, the greatest precaution is required in the fol- lowing cases, where a precipitate use of emetics may be attended with fatal effects, from bursting 3 blood vessel, &c. 1 . In all plethoric persons, but especially such as perceive g strong propulsion of the a blood
