173 
Table of Corrections for the Temperature. 
Dry SuBsTANCE, 
Temperature 
ot the o | 5 | 10 | 15 | 20 | 25 | 30 | 40 | 50 | 60 | 70 | 80 | 90 
Prisms | | 
in °C. 2 ees ee seal 
SUBTRACT. 
| 
20 0.53 | 0.54 | 0.55 0.56 | 0.57 | 0.58 | 0.60 | 0.62 | 0.64 | 0.62 | 0.61 | 0.60 | 0.58 
21 0.46 | 0.47 | 0.48 | 0.49 | 0.50 | 0.51 | 0.52 | 0.54 | 0.56 | 0.54 | 0.53 | 0.52 | 0.50 
0.74 0.40 | 0.41 | 0.42 | 0.42 | 0.43 | 0.44 | 0.45 | 0.47 | 0.48 | 0.47 | 0.46 | 0.45 | 0.44 
23 0.33 | 0.33 | 0.34 | 0.35 | 0.36 | 0.37 | 0.38 | 0.39 | 0.40 | 0.39 | 0.38 | 0.38 | 0.38 
24 0.26 | 0.26 | 0.27 | 0.28 | 0.28 | 0.29 | 0.30 | 0.31 | 0.32 | 0.31 | 0.31 | 0.30 | 0.30 
25 0.20 | 0.20 | 0.21 | 0.21 | 0.22 | 0.22 | 0.23 | 0.23 | 0.24 | 0.23 | 0.23 | 0.23 | 0.22 
26 0.12 | 0.12 | 0.13 | 0.14 | 0.14 | 0.14 | 0.15 | 0.15 | 0.16 | 0.16 | 0.16 | 0.15 | 0.14 
27 0.07 | 0.07 | 0.07 | 0.07 | 0.07 | 0.07 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.07 
App. 
ie : 
29 0.07 | 0.07 | 0.07 | 0.07 | 0.07 | 0.07 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.07 
30 0.12 | 0.12 | 0.13 | 0.14 | 0.14 | 0.14 | 0.15 | 0.15 | 0.16 | 0.16 | 0.16 | 0.15 0.14 
31 0.20 | 0.20 | 0.21 | 0.21 | 0.22 | 0.22 | 0.23 | 0.23 | 0.24 | 0.23 | 0.23 | 0.23 0.22 
32 0.26 | 0.26 | 0.27 | 0.28 | 0.28 | 0.29 | 0.30 | 0.31 | 0.32 | 0.31 | 0.31 | 0.30 | 0.30 
33 0.33 | 0.33 | 0.34 | 0.35 | 0.36 | 0.37 | 0.38 | 0.39 | 0.40 | 0.39 0.38 | 0.38 | 0.38 
34 0.40 | 0.41 | 0.42 | 0.42 | 0.43 | 0.44 | 0.45 | 0.47 | 0.48 | 0.47 | 0.46 | 0.45 | 0.44 
35 0.46 | 0.47 | 0.48 | 0.49 | 0.50 | 0.51 0.52 | 0.51 | 0.56 | 0.54 | 0.53 | 0.52 | 0.50 
WA’ WAZ, 
Example: Desired, the dry substance of a sample whose refractive 
index is 1.4589 taken at 26° temperature. The nearest index is 1.4567, 
which equals 67% then 1.4589 minus 1.4567 (the nearest value in the 
table lower than it) =.0022. In the decimal column opposite look for 
.0022 and one finds a value of 0.95. So the reading is 67.95 but at a tem- 
perature of 26° (from the table of corrections) .16 must be subtracted 
or the correct dry substance would be 67.79. In like manner the dry sub- 
stance of a sample with a refractive index of 1.5021 at 28° C. would be 
85.05, and one of 1.3802 at 28° would be 30.1, and one of 1.3655 at 33° C. 
would be 22.06. 
Bureau of Chemistry, 
Dept. of Agriculture, 
Washington, D, C. 
