OF GASES AT HIGH EXHAUSTIONS. 
409 
tlie negative pole and a platinum plate -for the positive pole. The apparatus is shown 
in fig. 12 . The reduction of the copper effectually obviates any chance of hydrogen 
coming off and contaminating the oxygen. The gas is received direct into a bell 
receiver in the acid liquid, and is thence transferred to the apparatus through a 
vacuum tap beyond the drying tubes, w, Plate 55, fig. 1 . The oxygen is always kept 
under a considerable pressure of water, and is only prepared shortly before it is 
wanted. The gas is passed into the apparatus very slowly through a considerable 
length of phosphoric anhydride. 
The following table gives the numerical results obtained :— 
Table II. — Log. 
dec. of oxygen gas at pressures between 
760 millims. 
0'76 millim. 
Temp. 15° C. 
Pressure. 
Log. 
Time of one complete vibration. 
Millims. 
decrement. 
Millims. 
Seconds. 
760 
0-1257 
775 
11-4 
720 
0-1247 
753 
11-3 
668 
0-1232 
623 
11-2 
632 
0-1222 
543 
11-1 
564 
0-1205 
' 443 
11-0 
562 
0-1204 
343 
10-9 
496 
0-1188 
202 
10-9 
458 
0-1178 
158 
10-9 
340 
0-1152 
93 
10-8 
318 
0-1148 
63 
10-8 
309 
0-1146 
27 
10-8 
301 
0-1145 
7 
10-76 
249 
0-1136 
1 
10-76 
200 
0-1130 
&c. 
159 
0-1126 
&c. 
150 
0-1125 
120 
0-1123 
103 
0-1122 
80 
0-1120 
72 
0-1120 
61 
0-1119 
47 
0-1119 
38 
0-1118 
30 
0-1118 
26 
0T119 
19 
0-1119 
16 
0T121 
12 
0-1122 
7-5 
0-1124 
3-8 
0-1121 
1-5 
0-1115 
1-4 
0-1111 
1-1 
0-1115 
1-0 
0-1115 
0-85 
0-1107 
0-76 
0-1102 
