Dimethyl-amido-azobenzol, 0.5 per cent. alcoholic solution.
Distilled water.
Esbach's reagent ([p. 74]).
Ether, sulphuric.
Ferric chlorid: saturated aqueous solution and 10 per cent. aqueous solution.
Haines' (or Fehling's) solution ([p. 78]).
Lugol's solution (Liquor Iodi Compositus, U.S.P.). Gram's iodin solution ([p. 38]) can be made from this by adding fourteen times its volume of water.
Obermayer's reagent ([p. 64]).
Phenylhydrazin, pure.
Phenol.