40 BULLETIN 466, U. S. DEPARTMENT OF AGRICULTURE. 
In this method specially standardized 100 ce flasks are used. 
Upon their necks are etched marks showing where 100 grams of 
recently boiled distilled water reach, at a temperature of 17.5° C. 
The correctness of all readings depends on this graduation. 
Twenty grams of the sample are weighed and transferred with 
water to one of these flasks. The sugar is dissolved by shaking, 
and the flask, after being filled almost to the mark with water, is 
allowed to stand in a constant temperature bath for 20 or 30 minutes 
with occasional shaking. The volume is then completed with water 
of the same temperature, the solution shaken, and a reading taken 
with the immersion refractometer, the temperature being noted at 
the same time with an accurate thermometer (better calibrated to 
one-tenth). Ifthe temperature is any other than 17.5° C., the reading 
obtained must be corrected by the figures opposite the temperature 
in Table XXVI. For readings taken at temperatures below 17.5° C. 
the correction is subtracted, and for readings at temperatures above 
17.5° C. the correction is added. 
TABLE XXVI.—Temperature corrections. 
Num- Num- Num- Num- 
Tem- Tem m. Tem- 
pera- maa pera- ber to pera- Peete pera- ber to 
pe Of Ce SN OP aC: 
15.0 0. 72 17.6 0. 03 20. 2 0. 82 22. 8 1. 62 
15.1 - 70 17.7 - 06 20. 3 - 85 22. 9 1. 65 
15. 2 . 67 17.8 - 09 20. 4 . 88 
15.3 . 64 17.9 -12 20.5 -91 |} 23.0 1.69 
15.4 - 61 20. 6 - 94 23.1 LSE 
15.5 -58 18.0 15 20. 7 -97 23.2 1. 75 
15. 6 55 18.1 Silke: 20. 8 1.00 23.3 1.78 
15.7 52 18. 2 21 20.9 1. 03 23.4 1. 81 
15.8 . 49 18.3 . 24 23.5 1.85 
15.9 - 46 18.4 27 21.0 1. 06 23.6 1. 88 
18.5 - 30 21.1 1. 09 23.7 1.91 
16.0 . 44 18.6 -33 21.2 1.12 23.8 1. 96 
16.1 -41 18.7 36 21.3 1.15 23.9 1. 99 
16. 2 38 18.8 -39 21.4 1.18 
16.3 -35 18.9 - 42 21.5 1. 22 24. 0 2. 03 
16. 4 32 21.6 1.25 24.1 2. 06 
16.5 29 19.0 45 21.7 1. 28 24, 2 2. 09 
16.6 26 19.1 48 21. 8 1.31 24.3 2. 12 
16.7 23 19.2 51 21.9 1.34 24. 4 2.15 
16. 8 20 19.3 54 24.5 | 2.19 
16.9 17 19.4 57 || 22.0 1.37 || 246 | 2:22 
19.5 61 || 22.1 1.41 || 24.7 | 2.25 
17.0 15 19.6 64 || 22.2 1. 44 24.8 | 2.29 
Wee | -12 LAT 67 || 22.3 1. 47 24.9 2.32 
17.2 - 09 19. 8 70 22. 4 1. 50 
17.3 - 06 19.9 7: 22. 5 1.53 || 25.0 2.35 
17.4 - 03 22. 6 1.56 || 25.1 2. 38 
17.5 - 00 20. 0 - 76 22.7 1.59 || 25.2 2. 42 
20. 1 Bris | 25. 3 2. 45 
1 Stanek, Zeit. Zuckerind. BOhmen, 35 (1911), p. 187. 
The percentage of the dry substance is then obtained from Table 
XXVITI. 
