( 613 ) 
Series | a@—d, (O) | d\—d, (C) | O—C abs. O—C in % | 
= == == — == = — eS SS eee ee — 
VI 0.9195 ...| . 0.9172, |, +--0.0023 4+ 0.2 | 
Vv | 7118 71874 — 0 0156 en 
Ill and IV 6502 6493 + 0 0019 + 0.3 
II 4714 4641 + 0 0073 dE 115 
| 
If we calculate the constant A of (1) from the values of d, and 
d, deduced in § 3, the following correspondence is found for d, and 
d, as expressed by equation (1) with the value A = 0.9758. 
l 
|| ea ee es | Ee 
| Series | d,(O) | a (C) | Oe | OC 7. (Oy | & (Cy LO. | OC 
AuTi ie | aaf ice Se ise) | E 
VI | 1.0268 | 1.0272 '—0.0004 0.0 | 0.1073") 0-11 19 |—0.0046 — 4.2 
| | | | | 
V | 0.9339 | 0.9424 —0.0085 — 0.9 1621 | 1566 +0 .0055 = 3.4 | 
| | | | | 
WandIV;} 8581 | 8574 +0.0007) + 0.1 || 2079 | 2094 ae eo — 0.7 
Ty ol) = 1557 | 7506 +0.0051| + 0.7 2843 | 2875 ee eA 
| | | 
The equations therefore give such results as might reasonably be 
expected from the accuracy of the observations, Slightly better results 
might of course be obtained by using least squares. The fact that 
the deviations of series V are on the whole greater than those of 
the other series may be explained by the suspicion already expressed 
that an error of observation has been made in that series, 
b. GOLDHAMMER’s © formula, for d,—d, is 
d, — d, = md (1 — t)*). 
With m= 3.496 the following correspondence is obtained : 
Series d,—d, (O) d,—d, (C) O—C abs. O—C in 0/, 
VI 0.9195 0 8840 + 0.0355 + 3.8 
V 7718 7731 — 0.0013 — 0.2 
III and IV 6502 6526 — 0.0024 — 0.4 
II 4714 4859 — 0.0145 — 3.1 
The correspondence as might be expected is not nearly so good 
as that with Kwrsom’s equation. 
1) D A. GOLDHAMMER. Zs. f. phys. Chem. 71. 577. 1910. 
2) This formula is almost identical with Kersom’s, for Kegsom gives for pentane 
0.3327 as the value of the index which I have called A. To get as good an agree- 
ment as possible, however, | have made an independent calculation of this index 
for argon. 
40 
Proceedings Royal Acad. Amsterdam. Vol. XIII. 
