^4] LOG two Species are remarkable, name- ly: 1. The Shielded Locuat, so called from the peAinai shield covering its breast. It is marked with a green- ish huo, but a deeper j-ellow be- neath its body, and the inside of •the hind legs is red : it attains the size of a robust rann's finger, and IS eaten in the East ; an instance of which occurs in Scripture, where it is recorded that St. John used this inseft as his food. 2. The Migrating Lr.nisl, which is of a -smaller size, has a greyish- blue head, yellowish and brown spotted wings above, green ones below, and a reddish belly behind. Its peculiar native soil is Great Tar- tary, whence the.-^e inse6fe have sometimes migrated into Europe, (flying at the rate of twenty-hve English miles in a da)), and com- mitted extensive devastations in corn-lields. They multiply more speedily than any animal in the creation, but are formidable only in the countries where they breed ; being unable to live in cold cli- mates. — In the year 1/48, a flight of these depredators was seen in Britain, bat they fortunately occa- sioned no damage. If, however, at fiiy future pfiiod, they should again invade this island, it will be advisable to burn, prei(ms;y to thfir approach, such combustililes as emit a thick and oti'ensive smoke j for instance, turf, wet straw, Szc. sprinkled with sulpliur. — An in- stance occuiTcd many years since, in Germany, where a swarm of locusts was driven from one dislrict to another, by the noise of bells, spades, hammers, and other me- tallic instruments. LOG -WOOD, Hcematoxylum Campechianum, L, an exotic plant, whi.h grows wild in the bay of LOG Campeacliy, Honduras, and other parts of the Spanish West Indies, where it rises from 1 6 to 24 feet in height. — In the beginning of the 18th century, it was introduced into Jamaica, where it is employed as a fence against cattle. — If the lower branches be pruned awav, while the tree is young, it will grow to a considerable size 5 and, when old, its wood will be of equal value to that imported from Honduras. — The trees are cut into billets, the bark and white sap of which are chipped off^, while the red part, or heart only, is s?lefted for sale. Logwood is used in great quan- tities for dyeing purple, green, blue, and especially for Hack coloui's ; according to the dilferent ingredi- ents employed. The last mentioned dyes, however, are not dinahle, unless previously tinged Iroivn, in a decoction of the dried Iceland Liverwort (see p. 11 7) ; which serves as the basis of li.King the co- louring matter. Indeed, there are many indigenous jMants that may be advantageously substituted for logwood, and other dyeirg drugs; a general survey of which, the reader will find in our General Judex of Reference, to be given at the con- clusion of the present work.— Hence we shall only add, on the authority of Poknek, that in all the experiments made with log- wood, he found alum, without add- ing any cream of tartar, to produce a better tflect than iii a state of combination m ith this acid ; and, for fixing or rendering the ditFerent colours more durable, blue vitriol was uniformly the most successful ingredient. Independently of its utility as a dyeing drug, logwood has lately been found to possess considerable ^s- trii^gency as a medicine : hence, a dcco6tion.