527 
1909-10.] Vapour Pressures of Solids and Liquids. 
5. The method is applicable to all solids, provided a non-interacting, 
non-solvent, non-volatile confining liquid can be found. When such a liquid 
cannot be found, a dynamic method, to be described in the next paper, may 
be used. 
The Vapour Pressures of Water . — The ease with which water may be 
purified, the relatively slight solubility of gases in water as compared with 
other liquids, the almost normal behaviour which water alone showed when 
studied by Tammann ( Wied . Ann., 32, 683) and by Wiillner and Grotrian 
(' Wied . Ann., 11, 545), and the relatively good agreement amongst the 
previous measurements of its vapour pressures, indicate water as the only 
suitable substance for testing the merits of the method. No other substance 
combines all these qualities. 
The measurements were made, by design, close to temperatures the values 
of which should be represented by whole numbers. The differences for 
one-tenth of a degree given by Eckholm were then used in making the small 
adjustments required to reduce each observation to the nearest whole number 
of degrees. The results are given in the table under “ S. and M. Observations.” 
The pressures in this column, therefore, are not smoothed results, but are 
essentially actual observations, subject to the irregularities which individual 
observations usually show. This enables them to afford a rigorous test of 
the method, while the adjustment facilitates comparison with the data 
obtained by other methods. 
Table. 
t. 
S. and M. Observations. 
H. and H. 
Differences H. and H. - 
S. and M. Observations. 
No. of 
Observations. 
P- 
Mm. 
Degrees. 
50 
3 
92-27 
92-30 
+ 0-03 
- 0-006 
51 
4 
97-03 
96 99 
-0-04 
+ 0-009 
55 
1 
117*87 
117-85 
-0-02 
+ 0-004 
60 
2 
149-13 
14919 
+ 0-06 
-0 010 
65 
3 
187-19 
187-36 
+ 0-17 
-0-019 
70 
3 
233-44 
235-53 
+ 0-09 
- 0-009 
75 
1 
288-78 
289-0 
+ 0-22 
-0-018 
80 
1 
354-90 
355-1 
+ 0-20 
-0-014 
85 
3 
433-54 
433-5 
-0-04 
+ 0-002 
89 
5 
505-87 
506-1 
+ 0-23 
- 0-011 
90 
1 
525-94 
525-8 
-0*14 
- 0-007 
For comparison, we give under H. and H. the values recently found by 
Holborn and Henning in the Reichsanstalt. These are smoothed results, and 
