DADYL 



93 



DARTER 



xylon, wood.] A coniferous plant, fragments 

 of which are found as driftwood in coal 



Dadyl, (da'dil). [G k. das, pine- wood or torch ; 

 hyle, material.]=Camphiuo, q.v. 



Daffodil, (dafo-dil). [Corruption of Aspho- 

 delus, the Latin name.]=Narcissus pseudo- 

 narcissus : a common meadow flower. 



Dafila=:Pintail ducks : birds belonging to 

 Natatores. 



Daguerreotype, (da-ger'o-tip). [M. Daguerre, 

 its inventor.] The earliest method of photo- 

 graphy, in which a silver plate was covered 

 with a coating of iodide and exposed in the 

 camera. 



Dahlia, (da/lia). [A. Dahl, a Swedish botanist.] 

 A garden flower, belonging to Asteracese, 

 much cultivated for its beauty. 



Dahomans, An African people. 



Daisy, (da'zi). [A.-S. daeyes eage, day's eye.] 

 =Bellis : a small meadow flower belonging 

 to Asteraceae. 



Dakosaurus. A Saurian animal, known only 

 by fossil teeth found in Oolite rocks : belongs 

 to Amphiscrelian reptiles. 



Daltonism, (dal'ton-izm). [Dalton, who suf- 

 fered from it. ] = Achromatopsy = Colour 

 disease : a condition of the eyes in which all 

 colours cannot be fully distinguished. 



Dalton's atomic theory, v. Atomic theory. 



Dam, (dam). [The Danish word.] A .wall 

 to resist the pressure of water. 



Damascene work, (dam'a-sen), [Damascus.] 

 =Damask work : 1. Inlaying one metal on 

 another so as to form figures, as on shields, 

 swords, &c. 2. Marking of patterns on 

 polished steel by the action of acids, or by 

 the combination of iron and steel. 



Damask-rose, (dam 'ask)= Rosa centifolia : a 

 rose marked by variety of colour. 



Dame's violet=Hesperis : an herb belonging 

 to Brassicacepe. 



Dammara, (dam'ma-ra). [The native name.] 

 1. A gum or resin, somewhat like copal, 

 obtained from the tree Dammara Australia 

 or Agathis, belonging to Conifers}. 2.= 

 Kauri pine : a tree belonging to Coniferae, 



Dammaric acid, (dam'ma-rik). [Dammara, 

 q.v.] An acid obtained from the kauri pina 

 or dammara. 



Damp, (damp). [Ger. dampf, vapour.] A 

 miner's term for vapours or gases found 

 in mines. v. Fire-d., Choke -d. t and 

 After-d. 



Damper, (dam'per). A contrivance for (1) 

 moderating the amount of draught in a 

 chimney or pipe ; or (2) for moderating the 

 vibration of the wires in a pianoforte. 



Damson, (darn'son). [Damascene, q.v.] A 

 plum -like fruit, a variety of Pruiius do- 

 mestica. 



Danaeaceae, (da-ne-a'se-e). [Signor Dana.]= 

 Danseads : tropical fern-like plants, the most 

 highly developed of Acrogens, forming a sub- 

 division of Filicales. 



Dandelion, (dan-de-li'on). [Fr. dent de lean, 

 lion's tooth.] = Taraxacum dens leonis = 

 Leontodon taraxacum : _ a _ common plant 

 belonging to Asteracese, 



Dane-wort, (dan-wurt)=Sambucus ebulus : a 

 plant, also called dwarf-elder, belonging to 

 Caprifoliaceaa. 



Daniell' s. [Professor Daniell, the inventor.] 

 D. battery=Const&nt batteiy : a galvanic 

 battery in which zinc is placed in sulphuric 

 acid, and copper in saturated sulphate of 

 copper ; the action of this is regular for 

 some days. D. hygrometer : an instrument, 

 for indicating the amount of moisture in 

 the air; a glass bulb containing a thermo- 

 meter in ether is cooled by evaporation 

 until dew is deposited. D. pyrometer : in 

 which very high temperatures are measured 

 by the expansion of a metallic rod. 



Danish * 'kitchen -middens. " [D. Kjokken- 

 inodding.] Refuse heaps, usually near the 

 sea, containing fragments of pottery and 

 instruments : proved to be very old by the 

 contained shells. &c. : belong to the Recent 

 Period. 



Danish peat. Peat moss in which stone tools 

 are found, and in which all fossil remains 

 are of existing species: belongs to Neolithic 

 Period. 



Dapedius, (da-pe'di-us). [Gk. dapedon, pave- 

 ment.] = Dapedium: a ganoid fish, known 

 only by fossil remains found in Lias rocks. 



Dajhnads, (daf'nads). [Daphne, g.v.]=Thy- 

 melacese : a sub-division of Daphnales. 



Daphnales, ( daf-na'lez. ) [ Daphne, q.v. ] 

 Shrubs and trees, usually evergreen, forming 

 a sub-division of Perigynous Exogens. 



Daphne, (daf'ne). [Gk. daphne, laurel.] 

 =Mezereon, &c. : a shrub with odorous 

 flowers, belonging to Thymalacere, named 

 from their somewhat resembling laurels. 

 D. to?reoa=Dwarf-bay. 



Daphnia, (dafni-a)= Water flea: a microscopic 

 crustacean, belonging to Branchiopoda. 



Daphnin, (dafnin). [Daphne, q.v.] A crys- 

 talline substance obtained from the bark of 

 Daphne mesereum. 



Daphnogene, (daf'no-jen). [Daphne, q.v.] 

 A laurel-like plant, found fossil in Eocene 

 and Miocene strata. 



Daphnoidea, (daf-noi'de-a). [Daphne, q.v. ; 

 Gk. eidos, form.] 1. A family of Ostracoda, 

 known by fossil remains. 2.=Thymelacea) : 

 a sub-division of Daphuales, q.v. 



Dare, (dar)=Dace, q.v. 



Dark lines of spectrum. A number of narrow 

 lines crossing a spectrum. Those in the 

 spectrum of sunlight are always the same, 

 and are used as standard, being named A,B, 

 C.D, &c. The lines A and B are in the red 

 ray, C between the red and orange, D,E,F,G, 

 and H are in the orange, green, blue, indigo, 

 and violet rays respectively. The number of 

 lines in the solar spectrum is very large, many 

 thousands having been already observed. 



Darnel, (dar'nel)=Lolium temulentum : a 

 common plant, the only one of the grass 

 kind which is poisonous. 



D~rt, (dart)=Dace, q.v. 



Darter, (dar'ter). l.=Plotus, snake-bird: a 

 bird belonging to Natatores, named from 

 its habit of darting at small fish. 2. A fish. 

 also, called archer fish, q.v. 



