98 New experimental Researches 
Tas_e IV, 
The observed Tension of ethereal Vapour compared with the 
Ratios 1-22, 1-23, Fc. and 1-22, 1-21, €'c. 
Temp. Quotients.| Expert, Temp. } Product.) Expert. 
104° | —— | 30-00 || 105° | —— | 30-0 
94 | 24-7 | 24-70) 115 | 36:6 | 35-9 
84 | 20-2 |20-:00 || 125 | 44:3 | 43-24 
74°} 163 {1610 |) 135 | 53-4 | 51-9 
64 | 13:06 | 13-00 |) 145 | 63-6 | 62:1 
54 | 103 /103 || 155. | 75-4 | 73-6 
44 { 8&1 | 81 | 165 | 88-2 | 86-4 
34 | 6235 | 62 | 175 |102-0 | 99-1. 
185 | 117-3 116-1 
195 | 134-0 133-7 
205 | 151-3 151-3 
1 
The numbers derived from calculation give a surprising ac- 
‘cordance with those observed in the lower range. In the upper 
range, the correspondence is as good as the delicacy of the ex- 
periments af such temperatures could permit us to expect. The 
experimep’ts have been presented without modification. I must 
own, thr st when first the above perfect coincidence appeared, it 
gave 1 no small pleasure, as it led me to suppose that I had 
disco” ered the hidden chain of nature. 
“a treating of the vapour of alcohol, Mr. Dalton considers it 
“48 irregular in the progress of its elastic force by heat, owing to 
? ts not being a homogeneous liquid. He suspects ‘ that the 
elastic force in this case is a mixture of aqueous and alcoholic 
vapour.”” I cannot see the cogency of this argument; for, if 
the separate bodies have a regular progression, the mixture ought 
not surely to be anomalous. I believe, however, that if the ex- 
periments were made with due accuracy, alcohol would be found 
as methodical in the elastic march of its vapour as other bodies. 
The following table will afford satisfactory proofs of the justness 
of these views. For absolute alcohol, the progression is pro- 
bably as simple as that of the preceding vapours. But for alco- 
hol, sp. gr. 0°813, which though highly rectified contains not a 
little water, we should expect it to result from a composition or 
modification of ratios. After some search on this principle, I 
accordingly found it. Starting from the boiling point 174°, or, 
for the convenience of comparison with the table, from the de- 
cade 170°, we move not by a unit, as before, but by a unit and 
a tenth ; or the initial ratio 1+26 is affected at each step or term 
of 
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