REDSHANK 



6523 



REDWING 



Red Spider. Common 

 garden pest 



Redshank (Tringa ' ' totanus). 

 British shore bird. It belongs to 

 the plover family. The plumage is 

 pale brown on the upper parts, with 

 a tail barred with black and white, 

 and whitish under parts. In winter 

 the plumage tends towards grey. 

 The legs and feet are bright orange 

 red, and the body is about 12 ins. 

 long. It is moderately common on 

 the sandy shores of the E. counties 

 of England, where it feeds upon 

 crustaceans and marine worms. Its 

 wider range includes Europe, Asia, 

 and Africa. 



Red Spider (Tetranychus tela- 

 riua). Eight-legged mite. It infests 

 the inhabitants of the greenhouse 

 , generally, and, 

 I in the open air, 

 particularly 

 carnations, 

 fuchsias, gladi- 

 oli, and roses. 

 The best green- 

 house treat- 

 ment is to 

 fumigate the 

 interior of the 

 structure with 

 sulphur. Inthe 

 open garden t he remedy is to spray 

 or syringe with one of the following 

 mixtures: (1) 1 Ib. of flowers of sul- 

 phur and 2 Ib. of fresh lime boiled 

 in 4 gallons of water. Then add 

 1 Ib. of soft soap, and, before 

 using, 3 more gallons of water. 



(2) The extract from 6 oz. of quas- 

 sia chips, 4 oz. of soft soap, and 

 half a pound of flowers of sulphur, 

 well mixed, in 5 gallons of water. 



(3) Paraffin emulsion. See Spider. 

 Redstart (Ruticilla plioenicurus). 



Migratory song-bird. It is to be seen 



between April and Sept. in most 



districts i n 



England, but 



is nowhere 



common. It 



is found in the 



N. and central 



regions of the 



Continent. 



The cock bird 



has bluish- Redstart. British 



grey plumage song-bird 



On the Upper W.S. RerrUge.F.Z.S. 



parts, with black throat and bright 

 bay under parts. The hen is red- 

 dish grey on the upper parts, with 

 pale red breast and flanks and whit- 

 ish throat. It is commonly found 

 about ruins, and makes its nest in 

 old walls. Its food consists of 

 insects and grubs. Ses Bird; Nest. 

 Red Triangle, THE. Emblem 

 of, and name popularly given to, 

 the Young Men's Christian Asso- 

 ciation. The red triangle on black 

 cloth was worn on the right sleeve 

 of the Y.M.C.A. uniform in the 

 Great War. A magazine of this 

 title was established in the same 



Redshank. Birds of the plover 



family, common on the sandy 



eastern shores of Britain 



W. S. Berridge, F.Z.S. 



period. The huts for soldiers organ- 

 ized by the Y.M.C.A. were known as 

 Red Triangle huts. See Young 

 Men's Christian Association. 



Reducing Agent. In chemistry, 

 a substance which removes oxygen, 

 chlorine, etc., from compounds. 

 Such substances are hydrogen, 

 carbon, aluminium, etc. The term 

 is used in a wider sense for any sub- 

 stances which bring about conver-. 

 sion into other substances. Some 

 compounds themselves act as 

 reducing agents, e.g. stannous 

 chloride, a compound much used 

 in testing for salts of mercury. 

 Sulphurous acid, ferrous sulphate, 

 sodium thiosulphate, and alcohol 

 have also special applications in 

 chemistry as reducing agents. Re- 

 ducing agents are indispensable in 

 reactions taking place in solutions, 

 and one of the chief is sulphuretted 

 hydrogen, which reduces ferric salts 

 to ferrous salts, arsenic acid to 

 arsenious acid, chromates to 

 chromic salts, and exerts its action 

 on hypochlorites, nitrates, sul- 

 phites, and thiosulphates, with 

 separation of sulphur. In analy- 

 tical chemistry, the reducing gases 

 of the Bunsen or blowpipe flame, 

 borax, potassium cyanide, etc., 

 are used in dry reactions. See 

 Chemistry. 



Reductio ad absurdum (Lat., 

 reduction to an absurdity). In 

 logic and mathematics, the de- 

 monstration of a proposition by 

 proving the absurdity of that 

 which contradicts it. Thus : two 

 straight lines perpendicular to a 

 third are parallel ; if they were not, 

 they would meet, and from the 

 point where they met two perpen- 

 diculars to one and the same 

 straight line could be drawn, which 

 is absurd. See Logic. 



Reduction. In arithmetic, term 

 used for changing the denomina- 

 tion of a quantity without chang- 

 ing its value. Examples are the 

 reduction of pounds, shillings, and 

 pence to pence, or the reduction of 

 separate fractions to a common 

 denominator. 



Reduction. In metallurgy, the 

 liberation of a metal from its ore. 

 Thus iron oxide is reduced in the 

 blast furnace to iron. The process 

 often requires more than one stage, 

 e.g. copper sulphides are reduced by 

 roasting to sulphates as the first 

 stage in a complex series of oper- 

 ations directed to the production 

 of the metal copper. See Furnace. 



Red Water. Disease which 

 affects cattle at grass. It occurs 

 only in summer and winter, and is 

 more frequent on high land which 

 has never been cultivated. It is 

 known in Scotland by the name of 

 moor ill. The cause of red water is 

 a minute parasite, similar to that 

 which causes malaria in man, con- 

 veyed by the common cattle tick. 

 So called from the red colour im- 

 parted to the animal's urine, it 

 affects cattle of any age. To pre- 

 vent the disease it is necessary 

 merely to keep the cattle off the 

 land for a year, and graze it with 

 horses and sheep, which are not 

 susceptible to the disease. See 

 Cattle. 



Red- water Tree (Erythrophloe- 

 um guineense) OR SASSY TREE. 

 Tall evergreen tree of the natural 



Red-water Tree. Leaves and flower- 

 beads of the West African tree 



order Leguminosae. It is a native 

 of W. Africa. It has small, yellow 

 flowers in terminal clusters. When 

 the tree is cut a red juice flows from 

 the incision. The bark is said to 

 be poisonous, and is used as an 

 " ordeal " by the natives for testing 

 the guilt or innocence of suspected 

 persons. An allied species (E. 

 laboucberii) is the Ah -pill of Queens- 

 land and other parts of Australia. 

 It has close-grained, hard, red 

 wood the hardest produced by 

 Australia which is used by the 

 natives for making wommeras and 

 spear-heads. 



Redwing (Turdua iliocus). Brit- 

 ish song-bird. It is related to the 

 thrush, which it greatly resembles 

 in general appearance. It is a 

 whiter migrant from N. Europe, 

 and as it feeds almost exclusively 

 on insects, it often suffers great 



