alpha-naphthylamine

The best way of proceeding is the following: Heat 1-3/4 lb. of alpha-naphthylamine in 10 pints of boiling water, agitating well until the base is very finely divided in the water, then 1-1/4 pints of hydrochloric acid is added, and the heat and stirring continued until the base is dissolved, then the mass is allowed to cool, 27 lb. of ice is added and 1-1/2 pints of hydrochloric acid.

The Dyeing of Cotton Fabrics A Practical Handbook for the Dyer and Student Franklin Beech

The developing bath is a little more difficult to make, owing to the fact that it is more difficult to get the alpha-naphthylamine into solution.

The Dyeing of Cotton Fabrics A Practical Handbook for the Dyer and Student Franklin Beech