928 
al | | | es = 
> 5 ee: =} SI 9 2 = 
ee ee 
Re tae cares 5 ei aise E 2 je) BAAS a £ 
iss} U 9 En ee | DS | 3 bs 
| | | aa | x | 5 ed a 
= — ee — ——— = == = 
0.644 0.9949 0.9952 0.9946 0.9948 0.9946 0.9947 0.9955 0.9947 0.9946 0.9945 
omen elen ENE or ee LC 
| | | 
be 1.0029 1.0027 1.0030 1.0028 1.0024 1.0023 1.0029 1.0030 1.0034 10030 
| | | | 
0.412 1.0067 1.0060,1 .0064 1.0063 1.0054 1.0070 1.0066 1.0971 1.0067 
0.436 1.0103 1.0106 1.0116 1.0089 1.0116 1.0114 
0.405 1.0152 1.0143, | | 1.0166 
The following interpolation formula was calculated using the method 
of least squares: 
eA ie ees -0,0056376  0,00005401 
6 Se 0.08086) ds EE 
n}— | As a 
in which 4 is the wave length in microns. 
The degree of accuracy of this formula is evident from the following 
table: 
“airy | (cal) | (obs) |Q X10 
‚a. 0.64385 » 0.99451 0.99446 5 
b 0.54608, 1 I | | 
c 0.50859, 1.00303 1.00304 — 1 
d 0.47221, 1.00672 1.00669 3 
e| 0.43585, | 1.01144) 1.01145, — 1 
f | 0.40467, | 1.01660) 1.01662) — 2 
| | | 
5. The dispersion of carbon dioxide. 
In the following table are given results of two series of measure- 
ments made with carbon dioxide. The gas used for the first series 
was only dried over calcium ‘chloride, and contained about 96°/, of 
carbon dioxide. The gas used for the second series was, in addition, 
distilled several times, and it contained 98°/, of carbon dioxide. The 
measurements were made in exactly the same fashion as in the case 
of hydrogen and of air. 
