zizyphus

[Lat., from Gr. zizyphon = the tree whose fruit is the jujube.] [See def.] 1. Bot .: A genus of Rhamnacee. Shrubs or small trees, with spiny stipules, alternate three-nerved leaves, a spreading five-cleft calyx, five hood-like petals, five stamens, a five-angled disk, adhering to the tube of the calyx, and having inclosed within it the two to three celled ovary. Fruit berry-like, the stone or kernel with two or three cells, and a single flattened seed in each. Widely distributed, but having their metropolis in the sub-tropical parts of the Eastern hemisphere. The berries of Zizyphus weight, 90; first obtained zirconite by Klaproth there typhus tween aluminium and silicium; symb., Zr.; atomic in 1789. Like silicium, it is capable of existing in three different states, amorphous, crystalline, and graph i to i dal. The amorphous and crystalline are obtained by proce es similar to those described for preparing the corresponding modifications of sili- cium (q. v.). The graph i to i dal variety is obtained sodium zirconite with iron. It is but slowly at in light scales of a steel-gray color, by decomposing tacked by sulphuric, nitric, or hydrochloric acid, even when heated, but di olves readily in hydro fluoric acid. zirconium-chloride, s. by heating zirconium in chlorine gas. Chem.: ZrCl4. A white crystalline ma prepared treated with water, it is converted into oxychlo ride of zirconium, ZrOC12,8OH2.