DAYYNE 9 



the two solutions are then separately filtered, and mixed together. The varnish thus 

 obtained is clear, and if exposed in a thin layer on a plate of glass it rapidly 

 solidifies. 



DAMMAR PITCH. A balsamic resin employed in India for incense, and 

 obtained from the Sal tree, the Shea robusta. 



DAMOURITE. A hydrated potash-mica, named after the French chemist, 

 M. Damour. 



DAMP, in mining, a term applied to dangerous exhalations, or rather gases, so 

 called from the German Damp/, vapour escaping from the mineral formations, or 

 accumulating in the workings. 



Fire-Damp, which occurs in coal-mines, is carburetted hydrogen gas. 



Choke-Damp, After-Damp, and Black-Damp, may be regarded as carbonic acid. 

 See MIKES, VENTILATION OF. 



35 AWAITS. A cobaltiferous mispickel. It has been proposed to unite under this 

 name all varieties of mispickel which contain cobalt. The name is complimentary to 

 Mr. J. F. Dana. 



DACTAXiITE. A silicate of the protoxides of iron, manganese, and beryllium, 

 v\-ith sulphide of zinc. It occurs in octahedral crystals, in granite, at Kockport, and 

 near Gloucester, in the State of Massachusetts. The mineral takes its name from the 

 American mineralogist, Prof. J. D. Dana, of Yale College. 



DAlffBITRITE. A silico-borate of lime, containing, when pure, silica, 48'9 ; 

 boric acid, 28 - 4 ; and lime, 22'7. It is found at Danbury, Connecticut, U.S. 



DANDELION. The Taraxacum Dens Leonis, a common British weed, belonging 

 to the Composites. It has a milky juice, which contains a bitter principle called 

 Taraxacine. Preparations of dandelion are employed in medicine as diuretics and 

 alteratives ; and dandelion root, when roasted, is sometimes used like chicory, as an 

 addition to coffee. 



DANK or DAWK. (A mining term.') Bands and beds of tough sandy clay, 

 more or less compact and homogeneous. It is probably derived from dough. 



BANNEIVXORXTE. An iron- and manganese-hornblende, from the iron-mines 

 of Dannemora, in Sweden. 



DAPHNE CANNABINA. The bark of this shrub, a native of Nepaul, has 

 been used for paper-making. 



DAPHNINE. The bitter principle of the Daphne alpina. 



DAPXCHO. A spongy kind of caoutchouc, which exudes from the roots of 

 the Siphonia elastica. It is used in South America for making stoppers. See CAOUT- 

 CHOUC. 



DARWXNXTE. A mineral consisting, according to David Forbes, of copper, 

 88-07 ; silver, 0'24 ; and arsenic, 1T69. It is found at Potrero Grande, south-east of 

 Copiapo, in Northern Chili. 



DASH WHEEIiS. These are revolving wheels having dash-boards, which are 

 much used in the washing-processes necessary in calico-printing, See BLEACHING. 



DATES. (Tamr, a date, Arabic.) The fruit of the Date Palm, The date tree, 

 Phoenix dactylifera, grows to the height of sixty feet. The dates are pulled before 

 they are ripe, and are then dried in the sun. These form one of the chief parts of 

 the usual food of the Arabs, while the seeds softened and ground down form the 

 nourishment for their camels. The leaves are employed for making mats. The 

 threads of the web-like integument at the basis of the leaves are twisted into ropes, 

 while the stems, when old, are used in the construction of houses. Tadmor, in the 

 Desert, built by Solomon, is supposed to derive its name from those trees, which grew 

 abundantly around it. 



BATHOZiZTE, or DATOIiITE. A b or o- silicate of lime, containing silica, 

 37'30 ; boric acid, 21-32 ; lime, 35'67 ; water, 5'71. It is found in fine glassy crystals, 

 of complex form, at Bergen Hill, New Jersey. 



D ATISCA, YELLOW. A yellow dye obtained by treating the aqueous decoction 

 of the leaves of the Datisca cannabina, a bastard hemp, growing in the Levant and in 

 India, with salts of lead. This yellow is obtained in a translucent mass, soluble in 

 water. Stuffs mordanted with alum are dyed a permanent yellow. 



DATURINE. A poisonous alkaloid found in the Thorn-apple (Datura Stra- 

 monium). Daturine closely resembles Atropine and Hyoscyamine. 



DAITCUS CAROTA. The common carrot. 



DAVIDSONITE. A greenish-yellow beryl, from Eubislaw, near Aberdeen, in 

 Scotland. 



DAVY LAMP. See SAFETY LAMP. 



DAVYNE. A Vesuvian mineral, consisting of silicate of alumina, soda, potash, 

 and lime. It is regarded as a variety of nepheline. 



