On Argon and its companions. 
73 
On mapping the ratios between the absolute temperatures of water and argon 
against the absolute temperature of water, a straight line is obtained, wliicli in its 
slope coincides with that obtained by us. In the table above. We see that the 
difterence between the values of Olszewski’s and our ratios is practically a constant 
one ; and the change of value between 372'27° and 538’6° for water is in each case 
0'0523. The position of Olszewski’s line is, however, different from ours; and the 
differences of temperature are shown in the following short table :— 
Pressure. 
Temperatures. 
Olszewski. 
Ramsay 
and 
Travers. 
Observed. 
Re-calculated. 
740-5 
86°1 
86-03 
87° 00 
18010 
132-9 
133-6 
135-1 
19230 
134-7 
135-1 
136-5 
20750 
136-8 
137-3 
138-6 
22040 
137-9 
138-2 
139-7 
22650 
138-6 
138-9 
140-4 
27210 
143-5 
143-5 
145-0 
28880 
144-4 
145-0 
146-5 
38460 
152-0 
152-6 
154-0 
It is evident that Olszewski’s temperatures are uniforndy Ijelow ours ; and we 
imagine that it may be attributed to his having used a constant-volume thermometer, 
whereas ours was a constant-pressure one. Mr. Baly, who lias made measurements 
of the boiling-points of oxygen and nitrogen with the same thermometer, finds 
results that also differ from Olszewski’s by 0'3G''’ for 0'^, and liy 0'15° for in the 
same direction (higher). On tlie whole, however, we may take Olszewski’s and our 
vapour-pressure curves as practically identical, save in the fact that their positions 
are not quite coincident. 
The Molecular Volanies of Argon, Krypton, and XeiMn. 
The apparatus by means of which the vohime of 1 cul). centim. of each of these 
gases at their boiling-points under atmospheric pressure was measured is shown in 
the figure (fig. G). 
After the apparatus had been completely exhausted of air through a, which was 
connected with the pump, the gas was introduced through an inverted siphon, 
and dried in transit with phosphoric anhydride; when a sufficient quantity had 
entered, the tube a was sealed. On raising the reservoir h, the volume of the gas 
VOL. CXCVII.-A. 
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