THE COMBINING VOLUMES OF HYDROGEN AND OXYGEN. 
409 
Table I. 
1 . 
Hydrogen 
excess. 
2. 
Hydrogen 
residue. 
3. 
Difference. 
4. 
Ratio of 
combining 
volumes. 
5. 
Atomic weight 
of 
hydrogen. 
c.c. 
c.c. 
c.c. 
1 
4-316 
3-439 
0-877 
2-00286 
1-00771 
2 
4-072 
3-140 
0-932 
2•00304 
1-00780 
3 
4-755 
3-877 
0-878 
2-00286 
1-00771 
4 
4-271 
3-366 
0-905 
2-00295 
1-00776 
5 
1-670 
0-750 
0-920 
2-00300 
1-00778 
6 
5-717 
4-844 
0-873 
2-00284 
1-00771 
7 
2-962 
2-044 
0-918 
2-00299 
1-00778 
10 
2-202 
1-309 
0-893 
2-00291 
1-00774 
11 
2-565 
1-576 
0-989 
2-00322 
1-00790 
12 
2-605 
1-699 
0-906 
2-00295 
1-00776 
13 
2-015 
1-179 
0-836 
2-00272 
1-00765 
14 
3-231 
2-340 
0-891 
2-00290 
1-00774 
Mean .... 
2-00294 
1-00775 
±0-00002 
Maximum deviation, 1 in 4000 
In the first few rejected experiments a small quantity of gas was condensed from 
the hydrogen residue in the spiral, »?. This gas was measured in the calibrated 
capillary at the top of the collector, 6. In the first experiment it amounted to about 
10 c.mm., falling to 2 c.mm. to 3 c.mm. in the second. Throughout the rest of the 
series the quantity was less than 1 c.mm. This gas was most probably carbon 
dioxide, produced by combustion on the walls of the explosion vessel of traces of 
organic impurities which previous cleaning treatment had failed to remove. Since 
the capillary exit tube from the explosion vessel was always full of mercury while 
the gases were being combined, there was no possibility of the flame reaching the 
grease on the tap, y. 
Second Series. 
Hydrogen, generated as in series 1, was purified by passage through the walls of a 
palladium tube. 
Oxygen was made and purified as in series 1. 
After four or five determinations, yielding somewhat discordant results, a crack 
was discovered in the palladium tube. A new tube, made from fused metal, was then 
set up. Of the following twelve experiments, two (Nos. 5 and 11), were rejected ; 
No. 5, because, owing to an accident, the determination was interrupted in the 
middle, and only completed after an interval of several days ; No. 11, because the 
yol. ccxvi.— a. 3 K 
