646  Mr.  Inglis  on  the  Isothermal  Distillation  of 
third  sample,  i.  e.  after  twenty  minutes   circulation  in  each 
case. 
The  apparatus  having  thus  shown  itself  accurate  and  con- 
venient for  working,  two  series  of  distillations  were  undertaken. 
In  the  first  of  these,  the  results  of  which  are  given  in  Table  II., 
twenty-three  mixtures  of  nitrogen  and  oxygen  were  distilled 
at  that  temperature  (74°*7  Abs.)  at  which  the  vapour-pressure 
Table  II. 
PN2/Po2=5'31.         C  =  6-60-O028  m. 
Temp.  74°'7  Abs.    Pure  oxygen  has  vapour-press.  =  100  mm. 
1 
Molec. 
percent. 
1   Molecular  percentage 
Nitrogen  in  Vapour : 
Total  Pressure 
mm. 
Part. 
Part. 
No. 
N2in 
liquid. 
!  Pressm*e 
Nitrogen. 
Pressure 
Oxygen. 
; 
1 
Obs. 
obs. 
:     calc. 
diff. 
obs. 
smoothed 
diff. 
1 
1 
% 
mm. 
mm. 
1... 
o-o 
o-o 
0 
100-0 
100-0 
00 
100-0 
2... 
5-3 
25-o 
26-5 
-To 
130-6 
130-0 
+  •5 
34-5 
95-5 
3''.! 
7-3 
•     343 
33-6 
+  -7 
140-7 
1410 
—  •2 
47-5 
93-5 
4... 
11-4 
44-5 
44-7 
—   -2 
162-9 
162-7 
+  1 
72-7 
900 
5... 
166 
55'5 
55-0 
+  -5 
190-2 
1900 
+  4 
104-5 
85-5     i 
6... 
21-0 
614 
61-5 
-  -1 
211-2 
2105 
+  •3 
1295 
81-0 
7... 
25-6 
66-5 
66-9 
-   -4 
232-2 
232-7 
+  4 
155-7 
77-0 
8... 
30-5 
71-2 
71-6 
-   -4 
254-5 
255-0 
-•2 
182-5 
72-5 
9... 
33-4 
73-6 
73-9 
-   -3 
267-1 
267-8 
—  •2 
197-9 
69-9 
10... 
37-5 
76-8 
767 
4-  'I 
284-8 
285-0 
-•1 
218-6 
66-4 
11... 
41-8 
80-0 
79-7 
4-  -3 
304-2 
303-7 
+  •2 
242-0 
61-7 
12... 
44-5 
81-5 
81-1 
+  -4 
3156 
315-0 
+  •2 
255-4 
59-6 
13... 
48-4 
830 
831 
-   -1 
330-1 
330-5 
-4 
274-6 
55-9 
14... 
52-2 
84-6 
84-G 
0 
346-4 
3467 
--1 
293  3 
534 
15... 
56-4 
86-4 
86-6 
—  -2 
361-1 
363-0 
-•5 
314-3 
48-7 
16... 
57-3 
87-2 
87-0 
+  -2 
366-0 
366-5 
-•1 
318-8 
47-7 
17... 
63-1 
89-2 
89-2 
0 
388-7 
3900 
-•3 
347  9 
421 
18... 
68-6 
91-0 
91 -1 
-  1 
408-5 
411-2 
—  -7 
374-6 
36-6 
19... 
74-8 
93-0 
93-0 
0 
4325 
435-5 
-•7 
405-0 
30-5 
20... 
79-2 
94-2 
94-3 
-  -1 
453-3 
4530 
+  4 
427-2 
25-8 
21... 
84-0 
95-9 
95-7 
—  "2 
467-5 
471-0 
-•8 
450-7 
20-3 
22 
88-9 
97-0 
97-1 
-    1 
489-7 
490-0 
-•1 
475-8 
14-2 
23!" 
93-9 
98-4 
98-4 
0 
509-8 
5090 
4- -2 
5008 
8'2 
24... 
994 
99-9 
99-9 
0 
5300 
529-0 
4--2 
528-5 
0-5 
25... 
(100-0) 
(100-0) 
(100) 
(531-0) 
(531-0) 
(531) 
of  pure  oxygen  is  100  mm. ;  and  the  total  pressure,  the  com- 
position of  the  vapour,  and  the  composition  of  the  liquid  were 
determined.  In  the  second  series,  which  was  carried  out  at 
79°'07  Abs.,  where  the  vapour-pressure  of  pure  oxygen  is 
200  mm.,  only  eleven  mixtures  were  taken ;  the  results  are 
given  in  Table  III. 
