

THY. 



IIIVK. 



Chlorine, in its pure and nncotnbined stats, U a gas of 



:. -grwnish colour. It has an ex< 

 Mid, to some persona, offensive nnell. If Enhabd, it 



citl-i" :i-;.'".\ \: .. .11, i .. I - M ' II' '* N ''" .-ii; 1 ..!.'! '" ">> 



branes in the throat and lung*, tu equivalent in 36'6 ; 



Init for .^liiianr calculations, it ia assumed, in rmjn 1 



iiiiniU.ru, to be 38, and i much denser than air, having a 



ravity of 2-5. Hence one volume of chlorine is 



two-and-a-half volume* in wdgtt of air. It 



rofore, be readily poured from ono vessel to 



IU combinations are Tery numerous ; the most 



,,f sodium, tlio niminon table 



alt, and t lime, which i to extensively used 



in the . .nn;: districts for bleaching purposes. 



The chief source of chlorine, for oomnMTCU and OHMT 

 purposes, ii common salt ThU in decomposed by means 

 of sulphuric acid and oxide of manganese, when the 

 v -I HUH becomes oxidised, and combine* with the sulphuric 



nn uilphate of soda ; and the chlorine 1 

 t hits set free, escapes in the form of a gas. A convenient 

 miwiu of producing chlorine by this or other means, is 



i I 



represented in the 

 annexed cut. The 

 materials are put into 

 a Florence flask, titled 

 with a bent tube ; the 

 latter passing to the 

 bottom of a clean jar, 

 the nock of which 

 should be loosely fit- 

 ted with a cork. The 

 flask is supported in 

 position by means of 



a ring stand ; and a gentle heat is to be applied by means 

 of a spirit-lamp. Wo should here observe, that as 

 chloriin 1 is rapidly absorbed by water, it cannot be 

 collected in the pneumatic trough ; and mercury must 

 not be used instead of water, because it is readily acted 

 ..u l,\- tli.- gas. We may here caution our readers that 

 inhalatior of chlorine gas produces the most painful 

 effects. An assistant left some bottles unlabelled, and 

 ln-ing unaware that such were filled with chlorine, we 

 had the misfortune to find the evil effects of inhaling a 

 considerable quantity, which resiilu-d in loss of voice, 

 and other severe and unpleasant symptoms. Should any 

 of our readers be similarly unfortunate, their remedy 

 will consist in immediately swallowing some unboiled 

 white of an egg, and applying to the nose a moderately 

 strong solution of ammoniacal gas (liquid ammonia of 

 the shops). 



Of course, the materials for producing chlorine from 

 common salt, <tc., should be added together in their 

 equivalent proportions, to obtain the proper amount of 

 clilorin.' I iy t'ii-ir mutual decomposition; but as they are 

 exceedingly cheap, this is a point of no great importance 

 when the gas is employed for laboratory or private ex- 

 [H-riments. There are, however, more convenient modes 

 '. t.iining chlorine on the small scale than that wo 

 ha\.- in. -nti. mill ; and to such we must now refer. 



Hydrochloric acid, to which wo have already referred 

 in ..ur former pa,'es, U a compound of chlorine with 

 hydrogen gas ; and if we can separate these elements, of 

 i->iirse we may obtain the chlorine or hydrogen free. 

 To separate the former is an easy matter. Some oxide 

 of manganese may be introduced into the flask, repre- 

 sented in Fig. 39 ; and then sufficient hydrochloric acid is 

 k h* added to moisten the powder. The two should In- 

 well mixed, otherwise the oxide of manganese may remain 

 as a dry powder on the bottom of the flask; and when 

 n applied, the acid may by chance run down, and, 

 '.inn the lifted |,rtion of the flask, will fracture it. 

 AfUT Unix forming a kind of paste, more acid is to be 

 kddi-d until a cream-like mixture is produced. The 

 iN-nt tub., in to he replaced, and a gentle heat may be ap- 

 plied to the flask, when the gas will be speedily prod. 

 Care should be taken that the materials in the tla-k do 

 ruth up and pan over into the jar re gas. 



This may arise either from too great a heat being 

 applied, or from the materials being too dry from a 



..f aeid Tin- hf.it limy gradually 



In' | m xi"-- 



i. Ix-im; heavier than the atmospheric air, ii! 

 place the Istterfrom the glass vessel into which it is pass- 

 ing, and, except for special experiments, it will be pure 

 h. If it be received in wide-mouthed stoppered 

 l-.tth s, the. neck should be slightly greased with t., 

 and the glass stopper may be then put in its place, being 

 at the same time turned once or twice in the neck, so as to 

 en-uro a gixxl distribution of the grease. The bottles, as 

 with all others containing gases, should be distinctly 

 l.-d to prevent mistakes ; and thus any quantity of 

 chlorine ma}' be prepared, and kept for experiments, 

 Clil..: ;uvd ill tlie chemical laborat 



Th.- student may try the following experiments, for the 

 purpose of becoming acquainted with the properties of the 

 gas. 



Experiment 19 Suspend a piece of cloth or paper, 

 dyed with any vegetable colour, and in a moist stat 

 a flower previously drenched with water, in a jar of 

 chlorine. The colour will be speedily discharged, owing 

 to tho bleaching powers of the gas. 



Chlorine, as we have already remarked, is largely 

 employed for the purposes of bleaching, and in some de- 

 partments of calico-printing, for discharging colours. It 

 is used in the form of chloride of lime, which is prepared 

 by passing gaseous chlorine over freshly slaked lime. 

 We shall have to refer more fully to the use of chloride 

 of lime, when we treat of the applications of chemistry to 

 arts and manufa. 



Experiment 20. Make a strong solution of litmus or 

 indigo in cold water, and pour this into a jar of cldorine 

 gas. The chlorine will be rapidly absorbed, and the 

 coloured liquid bleached.. 



Water or moisture is essential to the bleaching powers 

 of chlorine ; hence the dry gas does not bleach vegetable 

 colours. 



Experiment 21. Throw a few pieces of fused chloride 

 of calcium into a jar of cldorine, and leave them for m 

 time, so that they may absorb all moisture. Into the 

 dry gas introduce a piece of dry coloured cloth or paper, 

 but no bleaching effects will result. Indeed, it is 

 generally supposed that the bleaching effects of chlorine 

 really result from the decomposition of water. Tho 

 chlorine seizes the hydrogen of tho water, and sets the 

 oxygen free ; and this acting in a latent state on the 

 colouring matter present, at once Meaehes it. In former 

 times, before the discovery of chlorine, all cotton and 

 linen goods were bleached by exposing them to the 

 action of the sun, air, and moisture a process, however, 

 which was exceedingly slow and tedious. 



Chlorino has a limited power of supporting combus- 

 tion, as may bo seen by trying the. following experiment. 

 Efjti'riment 22. From a wire tixcd on a cork, suspend 

 a small piece of taper; and having ignited it, immerse it 

 in a jar of chlorine. The length of tho flame will lie in- 

 creased, and it will become dull and smoky, depositing a 

 sooty matter on the inside of the vessel. 



The gas has a very great attraction for some substances ; 

 and the production of li Jit and heat frequently results 

 from some- of its combinations as they take place. 



/: r/i: 11,11: ,il L';!. Introduce somo Dutch foil into ajar 

 of chlorine. The leaves will immediately catch fire, and 

 achlorideof copper will be produced. Antimony, A-c., 

 in a state of tine powder, which should previously Ix 

 warmed, will also ignite in a jar of chlorine, and produce 

 a chloride of antimony. 



Chlorine forms chlorides when combined with metals 

 itc. ; of which we shall speak when treating on th 

 bodies. It also combines with nitrogen, iodine, and 

 bromine, forming compounds therewith, which will be 

 fully described hereafter. With h\dn.-en it forms the 

 well-known hydrochloric acid, also eall.-d t itic" 



and " marine" acid, in the old chemical works. 

 Hydrochloric acid, in its pure state, is a ^'as coin]" 

 .-.piivalent of chlorine, united with oneof hydn" 

 Its equivalent is therefore !!(i'."i ; symbol, 11, Cl. In com- 

 merce, and in the laboratory, this gas is rmployi-d as a 

 liquid acid, being in combination with water. In this 



