BIBLIOGRAPHY
[1] Nissen. Zeit. f. Hyg., 1890, 8, 62.
[2] Delépine, J. Soc. Chem. Ind., 1911, 29, 1350.
[3] Phelps. Water Supply Paper No. 220, U. S. Geo. Survey.
[4] Wesbrook, Whittaker, and Mohler, J. Amer. Public Health Assoc., 1911, 1, 123.
[5] Lederer and Bachmann. Eng. Rec., 1912, 65, 360.
[6] Harrington. J. Amer. Waterworks Assoc., 1914, 1, 438.
[7] Ellms. Eng. Rec., 1911, 63, 472.
[8] Heise. Philippine Jour. Sci., 1917, 12, A, 17-34.
[9] Norton and Hsu, Jour. Inf. Dis., 1916, 18, 180.
[10] Langer. Zeit. f. Hyg., 1916, 81, 296.
[11] Longley. J. Amer. Public Health Assoc., 1915, 5, 920.
[12] Comte. J. Pharm. Chim., 1916, 14, 261.
[13] Massy. J. Pharm. Chim., 1917, 15, 209.