86 On two new Compounds [1820. 



muriatic acid gas. Having ascertained that water did not 

 interfere with the action of the substances, a small portion was 

 admitted into the vessel, which absorbed the muriatic acid gas, 

 and then another atmosphere of chlorine was introduced. 

 Again exposed to the light, this was partly combined with the 

 carbon, and partly converted into muriatic acid gas ; which 

 being, as before, absorbed by the water, left space for more 

 chlorine. Repeating this action, the fluid gradually became 

 thick and opake from the formation of crystals in it, which at 

 last adhered to the sides of the glass as it was turned round ; 

 and ultimately the vessel only contained chlorine with the accu- 

 mulated gaseous impurities of the successive portions, a strong 

 solution of muriatic acid coloured blue from the solution of a 

 little brass, and the solid substance. 



I have frequently carried the process thus far in retorts ; 

 and it is evident that any conveniently formed glass vessel will 

 answer the purpose. The admission of water during the pro- 

 cess prevents the necessity of repeated exhaustion by the air- 

 pump, which cannot be done without injury to the latter; but 

 to have the full advantage of this part of the process, the gases 

 should be as pure as possible, that no atmosphere foreign to 

 the experiment may collect in the vessel. 



In order to cleanse the substance, the remaining chlorine and 

 muriatic acid were blown out of the vessel by a pair of bellows, 

 introduced at the stoppered aperture, and the vessel afterwards 

 filled with water, to wash away the muriatic acid and other 

 soluble matters. Considerable care is then requisite in the 

 further purification of the chloride. It retains water, muriatic 

 acid, and a substance which I find to be a triple compound of 

 chlorine, carbon and hydrogen, formed from the cement of 

 the cap ; and as all these contain hydrogen, a small quantity 

 of any one remaining with the chloride would, in analysis, give 

 erroneous results. Various methods of purification may be 

 devised, founded on the properties of the substance, but I 

 have found the following the most convenient : The substance 

 is to be washed from off the glass, and poured with the water 

 into a jar ; a little alcohol will remove the last portions which 

 adhere to the glass ; and this, when poured into the water, 

 will precipitate the chloride, and the whole will fall to the 

 bottom of the vessel. Then having decanted the water, the 



