Lac

(lak). A resinous incrustation produced on the bark of the twigs and branches of various tropical trees (Urostigma religiosa, Mimosa cinerea, Butea frondosa, Schleickera irijuga, of Ceylon, India, and Burmah, Croton lacciferum, of Ceylon, Croton draco, Acacia greggii, Larrea men can a, of Mexico), by the puncture of the female lacinsect Carter i a (Coccus) lacca. This crude exudation constitutes the stick-lac of commerce. Shellac is prepared by spreading the resin into thin plates after being melted and strained. In the preparation of the shellac, the resin is freed from the coloring-matter, which is formed into cakes, and is known as I dye. See Pigments, Conspectus of. Button lac differs from shellac only in form, appearing in cakes about three inches in diameter and one-sixth of an inch thick. Bleached lac is prepared by di olving lac in a boiling lye of pearlash or pota ic hydrate, filtering and pa ing chlorin through the solution until all the lac is precipitated. Seed-lac is the residu tained after di olving out most of the coloring-matter contained in the resin. The common shellac is Laburnin (lab-er' -nin). Also called Cytisin. An alkaloid found in Cytisus laburnum. in varnishes, lacquers, and sealing-wax; the bleached lac in pale varnishes and light-colored sealing-wax. L.-beet, a fruit used in Siam for diarrhea Laburnum (lab-er' -num). The leaves of Cytisus laburnum, the properties of which are due to an alkaloid, cytisin. In small doses it is diuretic and resolvent; in larger doses poisonous, irritating the alimentary tract, and inducing purging, vomiting, and exhaustion. Unof. Labyrinth (lab' -ir-inth). A name given to the series of cavities of the internal ear comprising the vestibule, cochlea, and the semicircular canals. L., Bony. See L., O eous. L., Cortical, the intricately arranged collection of uriniferous tubules and blood-ve els filling the intervals in the cortical dyspepsia. L., Stick, lac as taken from tin on which it is formed. L. sulphur is, milk of sulpnecipitatum (U. S. P.) L., White. phur; sulphur lac. See Bleached Lacca (lak' -ah). See Lac.