654  Mr.  Inglis  on  the  Isothermal  Distillation  of 
Table  VIII. 
Carbon  Tetrachloride  and  Ethyl  Iodide.     49°-99  C. 
Concen- 
Concen. 
Concen- 
Concen. 
No. 
tration  of 
Pressure. 
Press. 
tration  of 
Pressure. 
Press. 
Iodide. 
Chloride. 
1 
0 
0 
153-4 
306-3 
•501 
2  ... 
5-8 
153 
•381 
148-6 
295-6 
•503 
3 
143 
38-4 
•373 
141-7 
280-8 
•505 
4 
31-8 
80-6 
•394 
127-3 
249-4 
•510 
5 
46-3 
1109 
•417 
115-4 
227-2 
•508 
6 
670 
153-1 
•437 
97-4 
1930 
•505 
7 
84-1 
183-4 
•459 
84-3 
167-5 
•503 
8 
186-7 
354-0 
•527 
0 
0 
Table  IX. 
Carbon  Tetrachloride  and  Benzene.     49°*99  C. 
No. 
Concen- 
tration of 
Chloride. 
Pressure. 
Concen. 
Press. 
Concen- 
tration of 
Benzene. 
Pressure. 
Concen. 
Press. 
1  ... 
2  ... 
3  ... 
4  ... 
5  ... 
6  ... 
i 
•    ... 
8  ... 
9  ... 
10  ... 
11  ... 
0 
8-4 
19-3 
28-9 
41-0 
48-0 
63-7 
89-0 
106-5 
119-8 
153-3 
0 
18-5 
40-5 
59  7 
82-9 
97-0 
128-7 
176-4 
211-8 
238-5 
306-3 
•455 
•477 
•484 
•494 
•495 
•495 
•505 
•503 
•502 
•501 
84-5 
799 
73-9 
68-6 
62-0 
58-2 
49-5 
35-6 
26-0 
18-7 
0 
268 
253-4 
237-1 
221-8 
202-5 
191-3 
165-8 
124-6 
93-4 
68-3 
0 
•315 
•315 
•312 
•309 
•306 
•304 
•299 
•286 
•279 
•273 
In  two  cases,  viz.  propylene  and  ethylene  bromide  and 
benzene  and  ethylene  chloride,  Zawidzki  found  that  the 
partial  pressure  of  either  component  o£  the  mixture  was  pro- 
portional to  its  molecular  percentage.  Now,  as  will  be  seen 
in  Tables  VI.  and  VII.,  the  change  from  molecular  per- 
centage to  concentration  upsets  this  relation ;  but  the  deviation 
from  Henry's  law  is  not  very  great,  and  any  association 
would  be  very  slight.  In  the  case  of  mixtures  of  carbon 
tetrachloride  with  ethyl  iodide,  Zawidzki  obtained  slightly 
curved  partial  pressure -lines  ;  but  it  will  be  seen  from 
Table  VIII.  that  the  carbon  tetrachloride  obeys  Henry's  law 
very  closely,  while  the  agreement  for  ethyl  iodide  is  not  so 
good.  Similarly  in  Table  IX.,  carbon  tetrachloride  and 
benzene  show  a  fair  agreement  with  Henry's  law.  It  must 
be  remembered  that  in  all  these  cases  the  concentration  has 
