CANE SUGAR. 



The Effect of Temperature on the Polarization of 

 Sugars. Although there is no doubt that the rotation of cane sugar falls 

 with a rise in temperature, in commercial sugars other factors are at work. 

 Browne 29 has conclusively shown that owing to the presence of levulose in low 

 grade sugars a rise in temperature is often accompanied by a rise in 

 polarization, and that the application of a temperature correction is invalid ; to 

 obtain a just ' polarization ' all sugars should be polarized at one standard 

 temperature, which is in the United States fixed at 20C. It is extremely 

 unfortunate that the Supreme Court of the United States has definitely settled 

 that legally the polarization of a sugar is the percentage of sucrose in that 

 sugar, and has also established the validity of temperature corrections, entirely 

 losing sight of the presence in commercial sugars of active bodies other than 

 sucrose. The polarization of a sugar is a useful trade convention but analy- 

 tically has no real meaning. 



REFERENCES IN CHAPTER XXII. 



1. /. 8. J., 92, 99. 



2. Ball. Assoc. 16, 337. 



3. J. A. C. S., 26, 186. 



4. Abs. in Jour. Soc. Chem. Ind., 1909, 805. 



5. /. 8. J., 93. 



6. J. A. C. 8., 1907, 926. 



7. Zeits. fur. Rub., 1875, 1054. 



8. Revue. Universette de la Fabric de Sucre, 1, 451. 



9. I. S. J., 56. 



10. /. 8. J., 61. 



11. Butt. U. S. Bur. Standards, 3, 105. 



12. Ber. Deut. Chem. Gesel., 10, 1414. 



13. Pub. Lab. Chem. Gen. Delia. Gab. Roma., 1891, 47. 



14. Ber. Deut. Chem. Oesel, 10, 1410; 17, 1757. 



15. Ber. Deut. Chem. Gesel, 20, 1848. 



16. Ber. Deut. Chem. Gesel., 21^, 2000. 



17. Zeits. fur Rub., 1888, 1028. 



18. /. S. J., 21. 



19. W. I. B., 6, 52; 7, 152. 



20. Comptes rendus, 107, 390. 



21. Chem. Centralblatt, 1907, p. 1320. 



22. An. Chem. Phys., 1849, p. 185. 



23. Zeit. Ver. Deut. Rub. Ind., 28, 699. 



24. Jour. Am. Chem. Soc., 28, 4. 



25. Trans. Chem. Soc., 1891, p. 46. 



26. Zeit. fur Rub. 2nd., 38, 867. 



27. Bull. Assoc., 23, 1143. 



28. Zeit. fur Rub. Ind., 39, 766. 



29. Am. Sug. Ind., XL, 176. 



30. Arch., 1904, 321. 



458 



