198 SCIENTIFIC AMUSEMENTS. 



bodies of the ordinary illuminating and combustible class, such as 

 candles, lamps, and coal gas flames. If a lighted candle be tied to 

 a wire and lowered into a jar of chlorine gas, the candle will not 

 go out entirely, but will burn with a dull red lurid flame, emitt ing- 

 clouds of smoke ; the carbon contained in the wax or tallow, &c., 

 of the candle does not combine with the chlorine under these 

 circumstances, and is consequently liberated as soot, whilst the 

 hydrogen present does combine with the chlorine, forming hydro- 

 chloric acid gas, and evolving sufficient heat in so doing to prevent 

 the flame from becoming completely extinguished. 



A jet of coal gas, burning at the end of a narrow glass tube and 

 connected with the gas supply by a flexible tube, will behave like 

 a candle, if lowered into a jar of chlorine. 



Expt. 218. Action of Chlorine on Oil of Turpentine. Soak a 

 piece of thin blotting paper in oil of turpentine, and then introduce 

 it into a jar of chlorine ; a vigorous action will at once commence, 

 and clouds of smoke and vapour of hydrochloric acid will be 

 emitted; if the jar be large enough, and the chlorine tolerably 

 pure, the action will become so energetic that the paper will take 

 fire, and a flame will be produced. This arises from the same 

 cause as that operating in the last experiment; turpentine contains 

 carbon and hydrogen combined together (being for that reason 

 termed a hydrocarbon) ; when brought into contact with chlorine 

 the hydrogen combines vigorously with the chlorine, whilst the 

 carbon is set free. 



Caution. In carrying out experiments with chlorine gas, such 

 as the last three, it is indispensable to operate either in the open 

 air, or at least in a freely ventilated room, unless a draught cup- 

 board (Expt. 145) be available to carry off the fumes ; if even a 

 very small quantity of chlorine escape into the air and be breathed, 

 most distressing coughing and irritation of the air passages will 

 inevitably be brought about; whilst serious injury may be 

 occasioned by breathing in larger quantities of the gas (compare 

 Expts. 162 and 180). 



Expt. 219. To prepare Carbon Monoxide. Place in a test- 

 tube or small flask half a teaspoonful of solid sodium formate, 

 and pour over it a little strong sulphuric acid (oil of vitriol); 

 effervescence will take place (especially if a little heat be applied), 

 owing to the escape of a combustible gas termed carbon monoxide, 

 which will burn at the mouth of the test-tube on applying a light. 

 By employing a generator with a delivery pipe turned down- 

 wards, the gas may readily be collected over water in the 

 pneumatic trough, as it is not easily soluble in water. The 

 chemical action taking place in this experiment is somewhat com- 



