SECT. II.] 
PROPERTIES OF STEAM. 
75 
Bettancourt’s boiling point is not stated, but appears to have been at 173°, 1 and 
his results like Dr. Robison’s are too small at low temperatures. 
Dr. Ure’s experiments are confirmed by those of Mr. Dalton, and may be relied 
on as approaching very near the truth. The formula, it will be observed, repre 
sents them with considerable accuracy. 
Of the Elastic Force of the Vapour of Sulphuric Ether. 
106. M. Cagniard de la Tour made several experiments on ether in the 
same manner as those on alcohol, art. 104. The ether was converted into vapour 
in a space less than twice its original volume by a temperature of 392°. This 
experiment was thrice repeated, with the same result, and 528 parts of air were 
compressed to 14, giving an elastic force of 37*7 atmospheres. 2 * * * 
107. Other trials were made, the results of which are shown in the following 
table. 
M. Cagniard de la Tour’s Experiments on Ether. 
Volume in the liquid state 7 parts. 
Volume in the liquid state 3J parts. 
Volume in the state of vapour 
Volume in the state of vapour 
20 parts. 
20 parts. 
Force as ex- 
Force of va- 
Temperature 
Force of vapour 
Differences. 
panding gas in 
Force of vapour 
Differences. 
pour in atmo- 
by Fahrenheit. 
in atmospheres. 
atmospheres, by 
in atmospheres. 
spheres, by for- 
formula below. 
mula below. 
212° 
5-6 
5-78 
234-5 
7-9 
2-3 
7-9 
257 
10-6 
2-7 
14-0 
1063 
279-5 
12-9 
2-3 
17-5 
3-5 
14-1 
302 
18-0 
5-1 
22-5 
5-0 
18-4 
324-5 
22-2 
4-2 
28-5 
6-0 
23-8 
347 
369-5 
392 
28-3 cf f , 
ni» py f fetate of 
vapour. 
48-5 
6-1 
9-2 
11-0 
/ State of 
\ yapour. 
50-5 
6- 5 
7- 0 
8- 5 
30-6 
38-7 
48-0 
414-5 
59-7 
11-2 
58-0 
7-5 
60-7 
447 
68-8 
9-1 
68-8 
63-5 
5-5 
82-3 
469-5 
78-0 
9-2 
70-5 
66-0 
2-5 
100-7 
492 
86-3 
8-3 
72-2 
70-5 
4-5 
514-5 
92-3 
6-0 
73-9 
74-0 
3-5 
537 
104-1 
11-8 
75-6 
78-0 
4-0 
559-5 
112-7 
8-6 
77-4 
81-0 
3-0 
572 
119-4 
6-7 
78-3 
85-0 
4-0 
594-5 
123-7 
4-3 
80-0 
89-0 
4-0 
617 
130-9 
7-2 
81-8 
94-0 
5-0 
1 Prony’s Architecture Hydraulique, vol. ii. p. 180. 
2 The experiments on sulphuric ether may be very nearly represented by the formula, 
/ = C i^ 8 ^ Q )i or lo S*/ = 6 0°g- R + 21 °) - 2-25212) 
when the ether boils at 104° or 105°; but for ether boiling at 98°, the constant logarithm should 
be 2-23953. 
In the above experiment the formula for ether boiling at 105° gives 48 atmospheres for its elastic 
force at 392°; but the correspondence with the tabular experiments is nearer.