LIQUEFACTION AND SOLIDIFICATION OF ARGON. 259 
Assuming the boiling-points of benzene, alcohol, and oxygen to be correct, those of 
argon could be calculated from them by multiplying the absolute temperatures of each 
substance by the corresponding ratio at each pressure. 
The observed and re-calculated absolute temperatures of argon and the differences 
are given below :— 









Pressure | Boiling-points (absolute) of argon. 
millims. | Observed. | From benzene. A. From alcohol. | A. From oxygen. A. 
| | 
| | | 
7405 | 86:1 86:1 0 | 86:1 0 86:1 0 
18010 | 1339 1331 —0°8 133:°1 | —08 133:3 —0°6 
19230 | 1347 134:7 0 1346 | Or 134-7 0 
20750 | 1868 136-4 —0-4 | 136°4 —0:4 | 1364 —0°4 
22040 | 137-9 137°8 —01 137:8 | =O | 137°6 —03 
22650 | 13886 138°5 —O1 | 138°5 —01 138°9 +0°3 
27210 | 1438°5 143-0 | —0:5 | 1430 —0'5 142°7 | —08 
28880 144-4 144-6 +02 | 144°6 | +02 144°3 —O01 
38460 15205) | 152:2 +0°2 | 152°4. | +0:4 152:0 | 0 


The comparison would, of course, be more valuable if there were some observations 
between 740 and 18,000 millims., but, so far as it goes, it will be seen that there is 
a very fair agreement between the observed temperatures and those calculated from 
the smoothed ratios. 
It is hardly likely, though not impossible, that so good an agreement would be 
obtained with a mixture or an impure substance. It is, at any rate, certain that a 
distinct want of agreement would have shown that the argon was not a definite, pure 
substance, and the results may be taken as affording additional confirmation of the 
conclusion that argon is a definite, hitherto unknown constituent of the atmosphere, 
and that it has been isolated in a state very closely approaching to purity. 
Ph Ivy, 
