HYDRIFORMIA 



174 



HYDROGEN 



negation of breathing. H. of phenyl= 

 Benzene, q.v. 



Hydrifonnia, (hi-dri-for'mi-a). A sub-division 

 of Polyps, by Hceven. 



Hydriodic acid, (hi-dri-od'ik). [Hydrogen and 

 Jodie. ] = HI = Hydric iodide: a colourless 

 fuming gas. 



Hydrindic acid, (hi-drin'dik). [Hydro and 

 /ndic.]=DioxindoL Derived from indigo. 



Hydrindin, (hl-drin'din). [Hydro and Indin.] 

 v. Indin. 



Hydro- (hl'dro). [Abb. of hydrogen, 3. .] A 

 prefix to the name of an acid that contains 

 no oxygen : as hydrochloric acid, hydrosul- 

 phuric acid, &c., and used generally to im- 

 ply the presence of hydrogen as an important 

 constituent. 



Hydrobenzamide, 0ii-dro-ben'za-mld). [Hydro 

 andBenzamide.] CaiHigNg: a crystalline sub- 

 stance; ammonia and oil of bitter almonds. 



Hydrobromic acid, (hf-dro-bro'mik). [Hydro 

 and Bromic, q.v.] = HB=Hydric bromide= 

 A powerfully-acid gas, resembling hydro- 

 chloric acid. 



Hydrocarbons, (h\-dr6-kar-bonz). [Hydro and 

 Carbon, q.v.] Compounds of hydrogen and 

 carbon, which belong to the inflammable 

 group of minerals: include naphtha, petro- 

 leum, asphalte, maltha, copalite, <fcc., marsh 

 gas, olefiant gas, cetylene, <fcc. //., when 

 oxdisied, form acids, alcohols, <tc. //. are 

 arranged in groups, according to number 

 of equivalents of C. and H. as follows: 



1st Series, CnH 2 n+2=Paraffins, q.v. 



2nd CnH 2 n=Olefines, q.v. 



3rd CnH 2 n-3=Acetylene series. 



4th ,, C&H2n-4=Quintone,terpenes,&c. 



6h CnH2n-6= Aromatic hydrocarbons 

 =Coal tar series=Benzol series. 



6th ,, CnH 2 n-8=Pheuylene,Cinnameue J 

 &c. 



7th CnH 2 n-io=-Cholesterene, <fcc. 



8th CnH 2 n-i2=Naphthalene. &c. 



9th ,, CnH 2 n-i6= StilDe n &c. 

 llth CnH 2n . 18 =Ant.hracene, &c. 

 12th CnH 2Q - 2 4=Chrysene, &a 



The 1st Series have been named methane, 

 quartane, quintane, bc. ; 2nd, methene, 



Suartene, quintene, &c. ; 3rd, quartine, quin- 

 ne, &c. ; 4th, quartone, quintone, &c.; 5th, 



quartune, quintune, <fcc., the vowels a, e, i, o, 



u, expressing the series in order. 

 Hydrocaryes=:Haloragaces8, q.v. 

 Hydrocaulus, (hl-dro-kaw'lus). [Hydro; L. 



caulus, stem.] The maiu portion of the 



ccenasarc of hydrozoa. 

 Hydrocephalus, (hl-dr5-sef a-lus). A trilobite 



found in Cambrian rocks of Bohemia. 

 Hydrocereae Balsaminaceae, q.v. 

 Hydrochserus, (hl-dro-ke'rus). An animal be- 

 longing to Rodentia. H. capybara=C&py- 



bara of S. America. 

 Hydrocharidacese, (hi-dro-kar-i-da'se-e). [Hy- 



drocharis, q.v.] Hydrocharads: fresh water 



plants, with flowers in scathes, belonging to 



Hydrales. 

 Hydrocharis, (M-drok'a-ris). [Hydro, q.v.', 



Gk. charts, grace.] = Frog-bit: a floating 



herb, the type of Hydrocharidaceae. H. mor- 

 8ttsrairc=Lesser Water Lily. 



Hydrochlorates, ( hi-dro-klo'ratz ). [Hydro 

 and Chlorate, q.v.] Compounds 01 hydro- 

 chloric acid and bases=Chlorides. 



Hydrochloric acid, ( hi-dro-klo'rik ). [Hydro 

 and Chloric, q.v.] = HC1 = Muriatic acid= 

 hydric chloride: a pungent colourless incom- 

 bustible gas, with intensely acid properties: 

 in solution, much used as a solvent. 



Hydrocomenic acid. CgHsOs! a yellow liquid. 



Hydrocorisae, (hi-dro-kor'i-ze). [Hydro, q.v.; 

 Gk. koris, bug. ]= Water bugs: insecta be- 

 longing to Heteroptera. 



Hydrocotyle, ( hi-dro-kot'i-le ). [Gk.Jiydor, 

 water; Kotyle, cup.] = Wliite rot = Penny- 

 wort : a small herb belonging to Apiaceae; 

 also called Sheeprot. 



Hydrocyanic acid, (hi-dro-sl'a-nik). [Hydro 

 and Cyanic, q.v.] Prussia acid = Hydrio 

 cyanide = formionitrile = HCN = HCy : a 

 colourless, very volatile inflammable liquid, 

 obtainable from the leaves and fruit of tho 

 peach, laurel, bitter almonds, &c. 



Hydrocysts, (hi'dro-sists). [Hydra, q.v.; Gk. 

 kystis, bladder. ]=Feelers: processes found in 

 some hydrozoa. 



Hydrodolomite, ( hl-dro-dol'o-mlt ). [Hydro 

 and Dolomite, q.v.] A mineral of the calcita 



Hydrodynamics, (hl-dro-dl-nam'iks). [Hydro 

 and Dynamics, q.v.] The science of the 

 motions of liquid bodies. 



HydroBcium, ( hi-dre'si-um ). [Hydra, q.v.; 

 Gk. oikos, house.] A cavity in hydrozoa, 

 into which the ccenpsarc can be retracted. 



Hydroelectric machine, for generating elec- 

 tricity by the friction of steam escaping 

 through narrow openings. 



a crystalline compound of ferricyanogen and 

 hydrogen. 



Hydrofluoric acid, (hi-dro-flu'5-rik). [Hydro 

 and Fluoric, 5.r.]=HF=Hydric fluoride: a 

 transparent volatile fuming liquid, which dis- 

 solves most of the metals, and etches glass. | 



Hydrofluosilicic acid, ( hi-dr6-fl-o-si-lis'ik ). 

 [Hydro, Fluo, and Silicic, g.v.J^Silicofluorio 

 acid, q.v. 



Hydrogen, (hfdro-gen). [Q^, hydvr, water; 

 gennao, to produce.]=H'; also called inflam- 

 mable air : a colourless, inodorous, tasteless 

 gas; the lightest of all known bodies; which 

 burns in contact with oxygen and forms 

 water; the standard for comparison of atomic 

 volume and weight of other gases : hypo- 

 thetically the first of the marsh-gas series. 

 v .Hydric. H. acetate=Acetic acid. H. ben- 

 zoate = Benzoic acid. H. borate = Boracic 

 acid. H. carbolate=Ca.Tbolic acid. //. chlo- 

 rute=Hydrochloric acid. H. cyanide= Hy- 

 drocyanic acid. H. dioxide=Hydroxyl. H. 

 gallate = G&UiG acid. H. phenate=PheniG 

 acid. H. pfiosphate=Phosphor:iG acid. H. 

 sulphate = Sulphuric acid. H. sulphide=z 

 Hydrosulphuric acid. H. sulphite = Sul- 

 phurous acid. H. far<rie=:Tartaric acid. < 



Hydrogen theory of boiler explosions; that 

 the contained water is decomposed by con* 



