on some of the leading doctrines of caloric, &c. 363 
trebling the force of its vapour a fifth part more heat than 
water does. 
I hope presently to be able to adduce satisfactory experi- 
mental evidence, that our thermometric indications are not 
at all so unequable as Mr. Dalton conceives. 
Meanwhile, in examining closely the table of the vapour 
of ether, a beautiful analogy with that of water presented 
itself. The series of ratios representing the progression of 
the latter being lowered a single step, will accurately fit the 
former. At 30 inches of elasticity 1.23 was our initial num- 
ber for aqueous vapour; for ethereal, it becomes 1.22; in- 
creasing or diminishing by unity each time in the second 
decimal figure, according as we descend or ascend by inter- 
vals of io° of the Fahrenheit scale. 
The following is a general view of the results. 
Table IV. 
The observed tension of ethereal vapour compared with the ratios 
1.22, 1.23, &c. and 1.22, 1.21, &c. 
Temp. 
Quotients. 
Expert. 
Temp. 
Product. 
Expert. 
104° 
— 
30.00 
105° 
30.0 
94 
24.7 
24.70 
"5 
36.6 
35-9 
84 
20.2 
20.00 
125 
44-3 
43-H 
74 
16.3 
16.10 
135 
53-4 
51.9 
64 
13.06 
13.00 
145 
63.6 
62.1 
54 
10.3 
10.3 
J 55 
75-4 
73- 6 
44 
8.1 
8.1 
165 
88.2 
86.4 
34 
6-35 
6.2 
i75 
102.0 
99-i 
185 
117-3 
116.1 
l 9 S 
134.0 
133-7 
205 ] 
iS»-3 
i5i-3 1 
The numbers derived from calculation give a surprising 
accordance with those observed in the lower range. In the 
MDCCCXVIII. 3 B 
