hydra headed

Having many heads, like a hydra, each of which is renewed as it is cut off; hence, difficult to get rid of, or having many sources or origins; multiform; spreading; not to be killed or quelled. ( Lit. & fig.) sin, aş; expect, Xenophon, exist. ph = f. hy-drăn-gě-ā-çě-æ, s . pl . [Mod. Lat. hydran ge (a); Lat. fem. pl. adj. suff. -aceæ .] Bot .: A family of Perigynous Exogens, alliance Sax if raga les. It consists of shrubs with opposite partly adherent to the ovary, four to six-toothed; petals four to six, deciduous; stamens in two rows, eight to twelve; fruit a two to five-celled capsule, with few or many minute seeds. Found chiefly in the temperate parts of this country and of Asia. Gen- era about nine, species forty-five or more. Some- times reduced to a tribe of Saxifragacem. hy-drăn-gě-ădş, s. pl . [Mod. Latin hydran- ge (a); pl. suff.- ads .] Zobl .: The polypite or proper nutritive zoõid of the Hydrozoa. hy-drar-gil-lite, s. [Pref. hydr- : Lat. argilla white clay, potter's earth, and suff. -ite ( Min .) IMG:content-1374.png:[blocks in formation] *1. Old Chem .: Quicksilver, mercury. 2. Pharm .: Hydrargyrum cum Creta. Mercury with chalk; also called gray powder. Obtained by rubbing one ounce of mercury with two ounces of prepared chalk till the globules are no longer vis i ble. It is a light-gray powder, insoluble in water. It is one of the mildest preparations of mercury. hy-drăs-tis, s. [From Gr. hydōr =water, refer- ring to the moist places in which it grows.] IMG:content-1375.png:[blocks in formation] hydric-bromide, s . [HYDROBROMIC-ACID.] hydric-chloride, s . [HYDROCHLORIC-ACID.] hydric-iodide, s . [HYDRIODIC-ACID.] hy-dri-dæ (1), hydra-dæ, s.pl. [Lat.hydr(a); fem.pl.adj. suff. - ide , -adœ .] Zool .: The typical and only family of the order Hydrid a (q. v.). *hy-dri-dæ (2), s. pl . [Mod. Lat. hydr(us); Lat. fem. pl. adj. suff. -ide .] Zool .: A family of Water-snakes, now called Hy- Chem.: A compound of hydrogen with another element, as Silicon hydride SiH, or with a hydro- carbon radical, as ethyl hydride, C2H H. hỹ dril-lạ, s. [Dimin. (?) of Lat. hydra = Gr. hydria =a water pot. Bot.: A genus of Hydro char i daceæ, tribe Valis. nereæ. The Jangi ( Hydrilla or Vallisneria alter- nifolia ) is one of the plants used in India to supply water mechanically to sugar in proce of being re- hy-drin'-dic, a . [Pref. hydro- (2); Eng. ind(igo), and suff. -ic .] (See the compound.) hydrindic-acid, s. adding ferrous sulphate to a boiling solution of azo benzoic acid in caustic soda, and precipitating the filtered solution by hydrochloric acid. It is a yellowish substance, slightly soluble in hot alcohol. thy-dren-çě-phal-o-çēle, s . [Pref. hydro- (1); Gr.engkephalos =the brain, and kēlē =a tumor.] Pathol.: A tumor or swelling, producing, on rupture, watery effusion on the brain. Not very different from hydrocephalus (q. v.). boiling isatin in water with a little zinc dust, and hydrochloric acid. It crystallizes in colorle prisms which turn yellow on on exposure to the air; it melts at 180° and decomposes at 115°, yielding ani- line. An aqueous solution of hydrindic acid is oxidized by the air, turning red. Chem.: A salt of hydriodic acid (q. v.). hy-dri-od-Ic, adj . [Eng. hydrogen); iod(ine), -ate .] and suff. -ic .] (See the compound.) hydriodic-acid, s . Chemistry: Hydric iodide, hydrogen iodide, HI. Hydriodic acid is a colorle gas forming in the air. At a pre ure of four atmospheres at 0° it is con- densed to a liquid. It can can be frozen at ordinary temperature by a mixture of ether and solid CO2 at a temperature of 55°. Its specific gravity is 4'3737, air=1. Hydriodic acid is prepared by the action of phosphorus and iodine in the presence of water, P+51+4H2=5HI+H3PO4. One part, by weight, of amorphous phosphorus is placed in fifteen parts of water, and twenty parts of iodine are added gradually. Then the flask is gently warmed, and the HI collected over mercury. H2SO4 does not liberate HI from pota ium iodide; the reaction is 3H2SO4+2KI=2KHSO4+12+SO2+2H2O. Hydriodic acid is not combustible, and will not support com- busti on. It is decomposed by pa ing it through a red-hot tube, the gas becoming violet-colored. HI is very soluble in water. A solution kept cold by ice will have a density of 1.990. The solution decom- poses in the air, water being formed and iodine liberated, which redi olves in the solution, turning it dark colored. A o'ution of HI in water di olves Zn, iron ore, with evolution of H, forming iodides, An aqueous solution of HI can be formed by pa ing H Sthrough water in which iodine is suspended, HO+HS+I=2HI+S+H2O. A solution having the density of 07 can be prepared in this manner. hydro- (1), pref. [Latinized form of Gr. hydro , the form in which hydor water, appears in a Greek prefix, especially before a consonant. Before a vowel it is generally hydr , Gr. hydr .] [Etym.] hydro-barometer, s. An instrument for deter- mining the depth of sea-water by its pre ure. hydro-extractor, s . [CENTRIFUGAL-MACHINE.] chin, bench; go, gem; thin, this; hydro camp a