[133] Private communication.
[134] U.S. Pat., 716,878, Dec. 30, 1902.
[135] Tea & Coffee Trade Jour., 1920 (vol. xxxviii: pp. 321–22).
[136] Jour. Amer. Chem. Soc., 1907 (vol. xxix: p. 1091).
[137] Ber., 1895 (vol. xxviii: p. 3137); 1899 (vol. xxxii: p. 435); 1900 (vol. xxxiii: p. 3035).
[138] Willcox & Rentschler. Tea & Coffee Trade Jour., 1910 (vol. xix: p. 440).
[139] Fricke, E. Zeits. f. angew. Chemie., 1889 (pp. 121–122).
[140] Willcox & Rentschler. Tea & Coffee Trade Jour., 1911 (vol. xx: p. 355).
[141] U.S. Pat., 897,840, Sept. 1, 1908.
[142] British Pat., 144,988, March 19, 1920.