Hematoxylon

(hem-at-oks' -Hon). Logwood. The heartwood of H. campechianum; it occurs as dark brown raspings or a coarse powder, and contains tannic acid and a coloring-principle, hematoxylin, that becomes grayish-red by the action of light. It is a mild astringent. H., Ext. Dose gr. v-xx. H., Decoctum, strength I to 17. Dose Unof.