415 
TABLE I. Hy. Values of pv ,. 
= = 2 es 
| Series NO. be | p dn seh Pp A SG 
| I Wed | 0.34786 | 4.7568 | 0.073129 
| 23 and 29 June 1911 |= eres | | | 
| ie | 0.60358 | 8.4597 | 0.071348 
— [ hed 
1h 0.10964 | 1.6918 | 0.064216 
Il. 
| | 
2 | 0.20672 3.2560 | 0.063469 | 0.000031 | 
| 24 June | | 
| 3 | )—255°.46 | 0.27759 4.4133 | 0.062898 0.000012 
‚8 and 14 July 1911 | | 
| 4 — 0.31318 5.0026 | 0.062603 0.000008 
5 0.31294 4.9992 | 0.062598 | 
| 
| 
IIT. sae | 
| 14 and 18 July 1911; | 
| el 
| 0.06698 | 1.1582 0.507834 
— 2570.26 | | 
| 0.13153 2.3031 | 0.057104 
The second series was represented by 
pva = 0,065043 — 0,00489 d4 + Cadat 
deduced from Nos. 1 and 5, with Cy as before, and the column 
O—C gives the differences between observation and calculation. These 
differences are smaller than those corresponding to the observed 
temperature fluctuations of the bath (see §4), which is in agreement 
with the assumption that it is the mean temperature of the bath 
which must be taken as the temperature of the gas in the piezo- 
meter. This series also supports the use of the assumed Cy. Series 
I and III, lacking the controls possessed by series II in itself, ave 
less reliable. Various circumstances have obliged us to postpone our 
TABLE II. 
H,. Individual virial coefficients By 
for hydrogen vapour 
fs Bay 
— 2520,63 | 0.000481 
— 255°. 46 0.000489 
— 257°.26 0.000638 
