[19] Norris, J. Ind. Eng. Chem., 11, 821 (Sept., 1919).

[20] J. Ind. Eng. Chem., 11, 292 (1919).

[21] Marshall, Lynch and Smith, J. Pharmacal, 12, 291-301 (1918).

[22] J. Pharmacol., 13, 1 (1919).

[23] Norris, J. Ind. Eng. Chem., 11, 825 (1919).

[24] Complete details of this work may be found in J. Ind. Eng. Chem., 12, 213 (1920).

[25] So-called “Triplex” glass.

[26] J. Ind. Eng. Chem., 11, 185 (1919).

[27] The basis of this chapter is the series of articles by Lamb and co-workers which appeared in the J. Ind. Eng. Chem. for 1919.

[28] Bancroft (J. Phys. Chem. 24, 127, 201, 342 [1920]) gives a comprehensive review of “Charcoal before the War.”