44 On two new Compounds [1820. 



inches, or twice the volume of the olefiant gas (barometer 29*1 

 inches). It was now placed for the day (Oct. 18) in the rays 

 of the sun ; but the weather was not very fine. In the evening 

 the solid crystalline substance had formed in abundance, and 

 very little fluid remained. When placed over chlorine, not 

 the slightest change in volume had been produced. The stop- 

 cock was now opened under mercury, and a small portion of 

 the metal having entered, it was agitated in the retort, to 

 absorb the chlorine ; the neck of the retort was left open under 

 the mercury all night, and the whole agitated from time to time. 

 Next morning (barometer 29*6) the mercury which had en- 

 tered, being passed into the neck of the retort, stood at a 

 certain mark 6 inches above the level of the mercury in the 

 trough, occupying 1*25 cubic inch, and leaving 24? cubic inches 

 filled by the expanded muriatic acid gas and nitrogen. These 

 volumes, corrected to the pressure of 29*1 inches, give 5*78 

 cubic inches for the chlorine absorbed, and 19*47 cubic inches 

 for the muriatic acid gas, &c. These absorbed by water left 1*2 

 cubic inch of nitrogen ; so that the gases in the retort, after 

 the action of solar light, were, 



Cubic inches. 

 Muriatic acid gas . .;.... . 18*27 



Chlorine : . . . . 5-78 



Nitrogen, &c 1*2 



and before that action, 



Chlorine \ ,.^ . . 29-25 



Olefiant gas . . . ..;,.,. . 5*0 

 Nitrogen .'*,* . . 1*0 



Hence 23*47 cubic inches of chlorine had disappeared, and 

 9*18 of these had entered into combination with an equal 

 volume of 9*13 cubic inches of hydrogen liberated from the 

 5 cubic inches of olefiant gas, to form muriatic acid ; and con- 

 sequently 14*34 cubic inches of chlorine remained combined 

 with the carbon of the 5 cubic inches of olefiant gas. Here 

 the volume of chlorine actually employed is not quite five times 

 that of the olefiant gas, nor the volume of muriatic acid gas 

 produced equal to four times that of the olefiant gas ; but 

 they approximate ; and when it is remembered that the con- 

 version was not quite perfect, and that the gases used would 



