DECAHEDRON 



95 



DEFLAGRATOR 



Decahedron, (dek-a-hed'ron), [Gk. deka, ten; 

 hedra, base.] A solid having ten regular 

 faces. 



Decandria, (de-kan'dri-a). [Gk. delta, ten; 

 aner, man.] A class of plants, the flowers 

 of which have ten stamens. A division m/ide 

 by Linnseiis. 



Decandrous, (de-kan'drus). [Decandria, q.v.] 

 Having ten stamens. 



Decapoda, (de-kap'o-da). [Gk. delca, ten: pous, 

 foot.] 1. A division of Crustacea, including 

 lobsters, crabs, &c., which have five pairs of 

 legs; fossil from Carboniferous times till now. 

 2. A division of Cephalopoda, including cut- 

 tle fishes in which the mouth has around it 

 ten arms or processes. 3. Do Blainville's 

 term for a division of Articulata, including 

 Crustacea, Limulus, and Decapoda proper. 



Decarburization, (de-kar-bu-ri-za'shun)! [L. 

 de, from; Carbon, q.v.] The removal of cai'- 

 boii from a compound containing it; ussd 

 especially for the conversion of pig iron into 

 malleable iron. 



Decaton, (dek'a-ton)=Fourth segment of abdo- 

 men in insects. 



Deci, (des'i). [L. decimus, tenth. ]=0ne tenth. 

 DecimetrerV metre; nearly 4 inches. 

 Decigram =rV gram; 1 grains. 

 Decistere = iV stere=Hectolitre; 61022 cubic 



inches. 



Decilitre =T^ litre^Gxo cubic inches. 

 Decime =jV franc: nearly Id. 

 v. Metric system. 



Decidua, (dc-sid'u-a). [L. deciduux, falling.] 

 The surface of the modified mucous mem- 

 brane of the uterus in man, apes, Cheirop- 

 tera, <fcc., during gestation, which at birth 

 falls away. 



Deciduata, (de-sid-u-o/ta). [L. decido, I fall.] 

 The division of Mammalia, including man, 

 apes, Cheiroptera, Insectivora, and Rodentia, 

 which have a decidua during gestation. 



Deciduous, (de-sid'u-us). [L. deciduus, falling 

 away.] Falling away. D. cypress=Ta3Lo- 

 dium distichum. D. leaves: which fall off. 

 D. plants: those which shed their leaves 

 every year. cf. Evergreens. 



Decimal, (des'i-mal). [L. decem, ten.] In- 

 creasing or diminishing by tens or powers of 

 ten. 



Deck, (dek). [A.-S. decan, to cover.] The 

 flooring of a ship. D. hooks, to connect the 

 deck with the stem and apron of a ship. D. 

 tfranso?ns=Deck-hooks at stern. 



Deckle, (dek'l)= Endless baud used in machi- 

 nery to communicate motion. 

 Declination, (dek-lin-a'shun). [L. declino, I 

 turn aside.] 1. D. of magnet ; angle between 

 the geographical N. and the horizontal 

 direction in which a magnet points when 

 freely suspended. D. compass: for ascer- 

 taining the magnetic declination at any 

 given place. 2. The distance of a heavenly 

 body above or below the celestial equator. 

 Decoction, (de-kok'shun). [Decoctum, the 

 Latin word.] An extract of an organic sub- 

 stance prepared by boiling. 



Decollated, (de-kol'lat-ed). [L. decollo, I be- 

 head. ]=Truncated : used of spiral shells, of 

 which the termination has been removed. 



Decomposition, (de-kom-po-zish'un). [L. de, 

 from ; compositio, compound.] The breaking 

 up of any compound into its constituent ele- 

 ments. D. by electricity: when an electric 

 current passes through a compound and 

 decomposes it. D. of light : the term used 

 to describe the conversion of white light into 

 coloured light, varying from red through the 

 colours of the spectrum to violet. 



Decompound, (de'kom -pound). [De and Com- 

 pound.]=Twice-compouud : used of leaves 

 that are doubly-pinnated. 



Decorticalia, (de-kor-ti-ka'li-a). [L. decortico, 

 I take the bark off.] A division of plants, 

 by Endlicher, q,v. 



Decorticated, (de-kor-ti-ka'ted). [L. decortico, 

 I take the bark off.]=Disbarked. 



Decrepitation, ( de-krep-it-0/shun ). [ L. de, 

 from ; crepitus, crackling.] Crackling : a 

 series of small explosions, when some sub- 

 stances are being heated. 



Decussated, ( de-kus'sa-ted',). [L. decussis, 

 diagonal crossing.] Crossed at right angles. 



Decussation, (de-kus-sa'shun). [Decussated, 

 q.v.] A crossing at right angles. 



Decyl hydride =CioHo2 a hydrocarbon of the 

 Marsh gas series. 



Deep-sea coral zone of life, Below 50 faths. 

 v. Zones of life. 



Deep-sea sounding. Usually by means of a 

 leaden block, of about 1 cwt., having tallow 

 at the bottom, by which samples of the sand, 

 shells, &c., are brought up. Other methods 

 1. A heavy weight and a fine line, which 

 is cut when the weight reaches the bottom, 

 and the distance known by measuring the 

 remaining line. 2. The deep seaclamm: a 

 pair of forceps and a weight, which are closed 

 when they strike the ground, and so enclose 

 some of the mud, &c. 3. The cup lead: a 

 long leaden weight, with a cup at the bottom, 

 closed by a leathern lid when filled. 4. 

 Brooke's apparatus: a hollow rod, carried 

 down by a heavy shot, which is detached oil 

 reaching the ground. 6. The Bull-dog sound- 

 ing machine: a large pair of scoops, carried 

 down by a large weight, which is then de- 

 tached. 6. The Fitzgerald sounding machine: 

 a modification of the Bull-dog. 7. The Hydra, 

 sounding machine: amodification of Brooke's. 

 8. Massey sounding machine: self-register- 

 ing. 



Deer, (der). [Deor, the A.-S. name.]=Cervus: 

 a ruminant quadruped, 

 belonging to the group {JJ^i/' 



of Cervidse, the males . _ f _*&~ i 



only of which have 

 deciduous antlers : ex- 

 cepting the rein-deer, E ffl 

 of which the female also 

 is horned. 



Definite integration. See 

 Integration. 



Deflagrator, (dc-fla-gra'- 

 tor). [L. deflagro, I Deer, 



burn up.] An apparatus for producing 



