1820.] of Chlorine and Carbon, c. 45 



inevitably contain a slight portion of impurity, the causes of 

 the deficiency can easily be understood. 



In other experiments made in the same way, but with smaller 

 quantities, more accurate results were obtained : 1 cubic inch 

 of olefiant gas with 1'25 cubic inches of chlorine, produced 

 by the action of light 3*67 cubic inches of muriatic acid gas, 

 4*963 of the chlorine having been used. 1*4 cubic inch of 

 olefiant gas with 12*5 cubic inches of chlorine produced 5*06 

 cubic inches of muriatic acid gas, 6*7 cubic inches of chlorine 

 having been used. Other experiments gave very nearly the 

 same results ; and I have deduced from them, that one volume 

 of olefiant gas requires five volumes of chlorine for its conver- 

 sion into muriatic acid and chloride of carbon ; that four vo- 

 lumes of muriatic acid gas are formed ; that three volumes of 

 chlorine combine with the two volumes of carbon in the olefiant 

 gas to form the solid crystalline chloride ; and that, when chlo- 

 rine acts on the fluid compound of chlorine and olefiant gas, 

 for every volume of chlorine that combines, an equal volume of 

 hydrogen is separated. 



I have endeavoured to verify these proportions by analytical 

 experiments. The mode I adopted was, to send the substance 

 in vapour over metals and metallic oxides at high tempera- 

 tures. Considerable care is requisite in such experiments ; 

 for if the process be carried on quickly, a portion of fluid chlo- 

 ride of carbon is formed, and escapes decomposition. The 

 following are two results from a number of experiments agreeing 

 well with each other. 



Five grains were passed over peroxide of copper in an iron 

 tube, and the gas collected over mercury ; it amounted to 3*9 

 cubic inches; barometer 29*85; thermometer 54 Fahr. Of 

 these nearly 3'8 cubic inches were carbonic acid, and rather 

 more than '1 of a cubic inch was carbonic oxide. These are 

 nearly equal to '5004 of a grain of carbon. Hence 100 of the 

 chloride would give 10 of carbon nearly, but by calculation 100 

 should give 10*19. The difference is so small as to come 

 within the limits of errors in experiment. 



Five grains were passed over peroxide of copper in a tube 

 made of green phial glass, and the chlorine estimated in the 

 same manner as before. 17*7 grains of chloride of silver were 

 obtained, equal to 4*36 grains of chlorine. This result ap- 



