CVAMKI.IDK. 



i YANOGEN. 



saturated with moisture, so thai when the bud* begin to grow they may 

 not exhaust the cutting of iu vital fluid by their excessive evaporation. 

 They an (haded with the aune object in view; sun-light increases 

 erapontion, and stimulates a growing part into action : the desire of 

 the gardener ia to guard against this till his cuttings have formed 

 abundant roots to feed by. When cuttings are very difficult to 

 strike, their lower end is often made to rest upon the bottom of 

 the garden-pot in which they are to grow ; this removes their wounded 

 end from too much moisture, and prevents their being gorged with 

 erode sap before they are able to digest it, an evil quite as great as 

 that of being exhausted by too rapid evaporation. The same or a 

 similar purpose is answered by putting the cuttings in the first 

 instance into pure silex (silver sand), from which they are removed 

 as soon as roots are emitted ; such sand permits only a slow trans- 

 mission of water through it, and is in fact incapable of supersaturation 

 if proper means are taken to drain it ; and hence it renders it im- 

 possible that water should be conveyed too quickly into the open 

 vessels of the cutting. 



In many cases a single leaf, or a portion of one, is left attached to 

 the upper eye of the cutting ; this is for the sake of keeping up a slow 

 circulation in the system, and of drawing into the vessels of the wood 

 a gentle current of moisture, so that the cutting may never be too 

 much exhausted. 



When cuttings will not strike because they are too young, the cause 

 in to be sought in the young tissue being too absorbent, and taking up 

 moisture faster than it can digest it, the result of which is a repletion 

 of the vessels, disease, and death. On the other hand, cuttings the 

 wood of which is too old will not strike from an opposite cause ; their 

 vessels are so clogged and rigid, that when the young leaves are ready 

 to expand, and the new roots to develop, the supply of food moves too 

 sluggishly through the cutting from point to point, and hence the new 

 parts wither if formed, or will not form at all. The exact age at 

 which a cutting roots most readily is a matter of experiment, and not 

 capable of being reduced to any theoretical rule. 



It is highly probable that if these points are well considered, all 

 plant*, of whatever nature, provided they have well-formed buds, are 

 capable of striking from cuttings ; and it is notorious, that while some 

 gardeners can only succeed with the commonest things, others, by the 

 success that attends their operations, possess what would seem a 

 magical power over plants, if we did not know tliat natural magic 

 consists in nothing more than the right application of right knowledge 

 at the right time. 



CYAMELIDE (C.HNO,). A white solid substance isomeric with 

 hydrated cyanic acid. [Cv ASIC AGIO.] It is non-crystalline, inodorous, 

 and insoluble in water, alcohol, ether, or dilute acids. It has no acid 

 properties. By heat it is volatilised and reconverted into hydrated 

 cyanic acid. Hot concentrated sulphuric acid decomposes it, sulphate 

 of ammonia is formed and carbonic acid evolved. It is not acted upon 

 when boiled with hydrocloric or nitric acids. Heated with caustic 

 potash, ammonia is disengaged and cyanate and cyanurate of the base 

 formed. 



CYAMELURIC ACID (3HO, C,.N t O,) is obtained in combination 

 with potash on heating mellonide of iwtassium [MELLON] with excess 

 of caustic potash ; the salt crystallites from an aqueous solution in 

 needles. The other ryamtlurala are obtained by double decomposition ; 

 some of them are crystalline. Cyameluric acid may be isolated from 

 a solution' of a cyamelurate by the addition of nitric or hydrochloric 

 acids ; it then falls as a white semicrystalline precipitate. Boiled with 

 nitric acid it gives cyanuric acid. 



CYAN CYANO, prefixes used in forming the names of certain 

 chemical substances into the composition of which cyanogen enters. 

 [CHLOR CHLOBO.] 



equivalents of hydrogen is replaced by phenyl (C,,H,V It is formed, 



\ " 

 as above indicated, by replacing the ammonia, BT < ! 9 in the prepare- 



( H 



lion of cyanamide by phenylamine (aniline! N < II . Cyanonilide 



I H 

 has not been obtained In crystals; it resembles in appearance common 



rc u, 



iline) V<S . 



la 



Two molecules of cyanamide and one of cyanic acid form amiiuline 

 [AMMELINE]. One of cyanamide and two of cyanic acid form 

 iimmelide. [AXMELIPK]. 



Chloroeyaamide (2NCyH,,CyCl), formed on adding solid rhWid.; 

 of cyanogen to solution of ammonia, contains two molecules of cyana- 

 mide and one of chloride of cyanogen. 



CYANANILIDE. [CYA.NAMIDK.] 



CYAXATKS. (CVAM,- ACID.] 



CYANETHINE (C.jH.jN,), is an organic base, polymeric with 

 cyanide of ethyl, and containing three molecules of that body. 

 C,,H,,N = (C,H,, SO,) 



Cjranethiiw. Cyanide of etbrl. 



Cyanethine is produced by the action of potassium on cyanide of 

 ethyl imperfectly dried ; hydride of ethyl U evolved and the residue 

 contains cyanide of potassium and cyanethine. It crystallises from 

 boiling water in pearly plates. Cyanethine forms salts with acids ; 

 thr nitrate (C,, H., N,,HO, NO,), crystallises in large colourless prisms. 



CYANIC ACID (C,HNO,=CyO, HO), is best prepared by distilling 

 dried cyanuric acid [CvAsriuc ACID], the receiver being kept cool by 

 a freezing mixture. It is a limpid colourless liquid of an exceedingly 

 penetrating odour, resembling very strong acetic acid. It acts upon 

 the skin as powerfully as red-hot iron, occasioning much pain. ' 

 acid ia very unstable, spontaneously changing in a few hours to on 

 opaque solid resembling porcelain. [CYAJI ELIDE.] During this change 

 no decomposition takes place, but the molecules probably undergo re- 

 arrangement. Water converts cyanic acid into bicarbonate of amiix >ni i. 



A combination of cyanic and hydrochloric acids has been obtained 

 by M. Wiihlcr. It fumes strongly in the air, and has an odour 

 resembling a mixture of the two acids. 



Cyanatct are nearly all formed by double decoin|> . itinn with the 

 potash salt. Cyanate of pntark (KO.CyO) is readily produced on 

 adding finely powdered oxide of lead to fused cyanide of potassium : 

 KCy + 2PbO = KO.CrO + Pb, 



Cyanide of Oxide of 

 potassium. lead. 



Cyanate of Metallic 

 potash. lead. 



CYANAMIDEl NCyH, = N^H ) is best prepared by passing 



\ {.H / 



gaseous chloride of cyanogen into a saturated ethereal solution of 

 ammonia (NH,). Chloride of ammonium deposits, and the ethereal 

 solution yields on evaporation white crystals of pure cyanamide. 



Cyanamide ia soluble without alteration in alcohol, and also in water, 

 but on evaporating the aqueous solution melamine results, a com- 

 pound containing three molecules of cyanamide. [MELAMINK.] Cyana- 

 mide fuses at 104, and recrystallises unchanged on cooling, but if the 

 temperature is raised to 300 it suddenly solidifies, evolves heat, and is 

 converted into inel.-unine. The addition of nitric acid to an ethereal 

 solution of cyanamide causes the assimilation of two equivalents of 

 water and formation of nitrate of urea. 



If, in the above process for the preparation of cyanamide, ammonia 

 be substituted by mrthylatnine, ethylamine, amylamine, diethylamine, 

 metbylethylamine, Ac., corresponding cyanamides are obtained, in 

 which one or both of the equivalents of hydrogen are replaced by 

 methyl, &c., forming monomethylcyanamide, monoethylcyanamide, 

 diamylcyanamide, Ac. ; or one equivalent of hydrogen may be replaced 

 by one radical and the other equivalent of hydrogen by another 

 radical forming a compound cyanamide, thus methylethylcyannmide 



f C H . 



Cyananilidr, N < Cy , is a compound similar to those just described : 



it is, in fact, phenylcyanamide or cyanamide in which one of the two 



The metallic lead and excess of oxide sink to the bottom of the 

 crucible and the melted mass may be poured out upon a plate. 

 It can be purified by solution in alcohol, and obtained in crystals by 

 evaporation. The lead gait (PbO, CyO) and the tllrtr talt (AgO. ( \ t >') 

 fall as white precipitates on mixing solution of cyanate of potash with 

 solutions of nitrate of lead or nitrate of silver. 



Cyanate of ammonia (NH.O, CyO), in solution, is after a time 

 entirely changed into urea. [UREA.] The same transfonnatioi i 

 immediately on boiling the solution. No decomposition occur; in 

 either case. [CYANOGEN.] 



CYANIC AMIDE. [CYANAMIDE.] 



CYANIC ETHER. [ETHERS.] 



CYANIDES. [CYANOGEN.] 



CYANILIC ACID (3(HO, CyO), is mctameric with cyanuri 

 The two acids resemble each other very closely, but the formrr ia 

 much more soluble than the latter. Cyanilic acid is formed on Imilini; 

 hydromellon [MELLON] with nitric acid. It crystallises in efflorescent, 

 oblique, rhomboidal prisms. Strong sulphuric acid converts it into 

 cyanuric acid. 



CYANIL1NE (C.,H,N, Cy). Aniline absorbs cyanogen, and after a 

 time deposits crystals of a basic substance capable of com) lining with 

 acids like aniline itself. It is formed by the direct union of the 

 cyanogen and aniline, and is called cyaniline. It is \, i\ ,-li-litly 

 soluble in cold alcohol, and but little more so in boiling alcohol. It 

 fuses at about 420 Fair., and at a higher temperature is decomposed. 

 Both cyaniline and its salts are very unstable. 



CYANIN. MM. Fremy and Cloei have given this name t.. the 

 colouring matter that produces the red and blue tints of various 

 flowers, the red becoming blue in the presence of an alkali, or, if the 

 latter is in excess, assuming more or less of a green tint : in the same 

 way an acid causes blue cyanin to assume a rose colour. 



Cyanin maybe obtained from the petals of the violet or iri< In- 

 digestion in boiling alcohol. It has never been obtained sufti. 

 pure for analysis. Deoxidising agents decolorise it, ami it 

 becomes coloured under the influence of oxygen. It is uncrystalli-ililr. 

 [COLOURING MATTERS.] 



CYANOGEN (NC,=Cy). A gaseous compound of the cl'-' 

 nitrogen and carbon, in the proportions of one equivalent of the former 

 and two of the latter. or fourteen parts by weight of nitrogen, and 

 twelve of carbon. It was discovered in the year 1815 by Gay I 

 though some of its compounds were known long before Iliat date. 



