VARIATION' OF MOLFOULAR SURFACE-ENERGY WITH TEMPERATURE. 671 
Ethyl Alcohol. 
t. 
h- 
i>- 
fT. 
7- 
0 
20 
raillim?!. 
millims. 
44-00 
millims. 
43-80 
0-7926 
0-0001 
dynes. 
22-03 
40 
41-14 
0-7754 
0-0003 
20-20 
60 
38-44 
0-7572 
0-0008 
18-43 
80 
.33-60 
36-40 
35-56 
0-7377 
0-0017 
16-61 
90 
31-40 
•34-05 
34-05 
0-7283 
0-0025 
15-63 
100 
.30-00 
32-50 
32-.50 
0-7174 
0-0035 
14-67 
no 
28-50 
30-80 
31-00 
0-7057 
0-0049 
1.3-69 
120 
27-20 
29-30 
29-30 
0-6925 
0-0066 
12-68 
130 
25-50 
27-45 
27-56 
0-6789 
0-0088 
11-63 
140 
24-00 
25-80 
25-70 
0-6631 
0-0115 
10-59 
150 
22-20 
23-80 
23-76 
0 6488 
0-0149 
9-52 
160 
20-40 
21-80 
21-75 
0-6329 
0-0192 
8-4.5 
170 
18-35 
19-60 
19-65 
0-6165 
0-0245 
7-34 
180 
16-10 
L7-20 
17-45 
0-5984 
0-0311 
6-23 
190 
14-10 
15-00 
15-08 
0-5782 
0-0.397 
5-13 
200 
11-75 
12-50 
12-40 
0-55.58 
0-0508 
3-99 
210 
9-30 
9-90 
10-00 
0--5291 
0-0655 
2-91 
220 
6-80 
7-20 
7-20 ■ 
0-4958 
0-08.54 
1-87 
230 
4-00 
4-20 
4-20 
0-4550 
0 1135 
0-91 
234 
, , 
3-06 
0-4292 
0-1296 
0-59 
235 
2-30 
2-45 
2-80 
236 
2-42 
0-4184 
0-1401 
0-43 
240 
1-60 
1-65 
1-10 
0-3825 
0-1715 
0-15 
243-1 
• • 
0-2756 
0-2756 
Experiments at Low Temp)eratures. 
To measure the capillary rise at — 89°'8, the temperature of nitrous oxide boiling- 
under atmospheric pressure, an arrangement different from that described was resorted 
to, A tube, about 2 centims. wide and 20 centims, long, was sealed at one 
end; into it was inserted a capillary tube of known diameter, provided with three 
glass struts or knobs at each end, so as to make it stand vertically in the wider tube. 
After the capillary tube had been introduced, the wider tube was drawn off at its 
upper end, to form a narrow neck, through which it could be exhausted. The pure 
I liquid was then introduced, and, after the tube had been rinsed with it several times, 
3 or 4 cub. centims. were left in ; the tube was then exhausted, and the liquid was 
made to boil under reduced pressure for some time, so that its vapour might expel all 
traces of air. 
The capillary neck was then sealed. Observations were made of the capillary 
ascent at the ordinary temperature, the whole tube having been immersed in v^ater 
for this purpose. It was then placed in a double-walled tube containing liquid 
nitrous oxide, with a few shreds of platinum at the bottom, so as to keep the liquid 
in constant ebullition. Such double-walled tubes, from the space between the walls 
of which the air has been exhausted as recommended by Dewar, make it possible to 
