ox EVAPORATION AND DISSOCIATION. 
130 
Experimental Hesults. 
Vapour-Pressures at Low Temperatures. —These were determined by our dynamical 
method. The thermometer had been standardized by determinations of the vapour- 
pressures of water ; its zero point was redetermined. 
Table I. 
Pressure. 
Temperature. , 
Pressure. 
Temperature. ^ 
Pressure. 
Temperature. 
mms. 
0 i 
mills. 
0 1 
j mms. 
5'25 
5-5 
34-5 
33-7 
' 235-35 
69-5 
540 
4-9 
42-05 
36-95 
240-1 
70-0 
5'25 
5-5 1 
50-05 
40-0 
! 273-7 
72-85 
6-10 
7’5 1 
57-55 
42-3 
312-85 
75-85 
7-25 
9-7 ! 
67-6 
45-2 
355-8 
78-8 
870 
12-8 ! 
79-7 
48-2 
404-9 
81-9 
9-20 
13-4 
94-6 
51-4 
455-5 
84-6 
lO'oo 
15-6 
110-95 
54-5 
505-6 
87-0 
13-30 
18-7 ! 
1.30-8 
57-6 
561-9 
89-6 
16-40 
21-75 1 
151-85 
60-5 
615-1 
92-0 
20-30 
25-1 i 
175-3 
63-4 
672'7 
94-3 
24-55 
28-2 
201-1 
66-2 
j 760-7 
97-5 
29-.35 
31-1 
204-8 
66-7 
These results were plotted on sectional paper, curves drawn through them, and the 
pressures corresponding to equal intervals of temjierature read off. 
Specific Gravity of Propyl Alcohol. —A Sprengel’s tube of the form recommended 
by Perkin was employed. The weighings were reduced to a vacuum:— 
Weight of water at 16°’7 
Capacity of tube at 1G°7 
Weight of alcohol at 0° . 
Capacity of tube at 0° 
Specific gi’avity at 0° 
Volume of 1 grm. at 0° . 
Weight of alcohol at 10°'72 
Capacity of tube at 10°72 
Specific gravity at 10°72 
Volume of 1 grin, at 10°72 
.15'3169 grms. 
.15‘3339 c.cs. 
.12‘5577 grms. 
. 15*3275 c.cs. 
. 0*81929. 
. 1 *22056 c.cs. 
12*4338 grms. 
15*3316 c.cs. 
0*81099. 
1*23306 c.cs. 
The results of other observers* are not very easy to compare with ours ; some of 
them are given in terms of water at 0°, others at 4°, and others again at the same 
* A tabulated .statement of determinations of tbe boiling-point and specific gravity of propyl alcohol 
is given by LossEX, ‘ Annalen der Chemie u. Pharmacie,’ vol. 214, p. 10.5. 
