542 



Prof. J. Dewar. 



[June 17, 



Liquefaction of Carbonic Acid with Tetrachloride of Carbon. 



The quantity of tetrachloride of carbon was a little less than the 

 volume of the liquid carbonic acid. 



At 12°' 8 0. the surface of the liquid appeared agitated as soon as it 

 appeared in sight, and on increasing the pressure, a distinct layer of 

 carbonic acid was formed on the surface of the tetrachloride ; on in- 

 creasing the pressure, a still more distinct layer was formed which, 

 however, on standing, rapidly commenced to dissolve in the tetra- 

 chloride, and in about ten minutes it was perfectly homogeneous. 



At 21° "4 C. the surface of the tetrachloride appeared agitated when 

 it came in sight, a layer of liquid being formed on increasing the 

 pressure, as at 12° C. 



At 30° C. liquid was also formed, which, however, rapidly diffused 

 into the tetrachloride of carbon. 



At 40° C. the liquid also appeared agitated, and on increasing the 

 pressure rapidly, a small quantity of fluid was condensed, which, how- 

 ever, rapidly disappeared in the tetrachloride. 



At 52° C. the liquid again became agitated, and on increasing the 

 pressure, a distinct layer of liquid was formed. 



The same took place at 58° C. 



Liquefaction of Carbonic Acid and Chloride of Methyl. 



When chloride of methyl was compressed in a tube by itself, it 

 became liquid before the pressure could be registered, and must have 

 been below 10 atmospheres. 



When compressed with about twice its volume of carbonic acid at 

 13° '5 C, the chloride of methyl, of course, liquefied first, and at about 

 27*67 atmospheres, its surface became agitated, showing that the 

 carbonic acid had commenced to liquefy, but the exact point was 

 difficult to ascertain, as it dissolved so very rapidly in the chloride of 

 methyl. 



At 20°'05 C. this point appeared to be at 28' 57 atmospheres. 



At 30° C. some liquid was also condensed, but the pressure at com- 

 mencement of liquefaction could not be taken, as it mixed so rapidly 

 with the chloride of methyl. 



That more liquid was in reality condensed, was seen by the 

 lengthening of the liquid column, and by its boiling out of the 

 chloride of methyl when the pressure was reduced. 



At 40° C. exactly the same took place. 



Carbonic Acid and Acetylene. 

 About equal volumes of these gases were compressed together ; they 

 liquefied and mixed completely at all the temperatures given below, 

 and no appearance of two different gases being liquefied could be 

 detected, except that the liquid was strongly agitated during condensa- 



