This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Dissolve, by the aid of heat, 40 parts of white castile soap, shaved fine, in 1,200 parts of soft water, and to the solution, when cold, gradually add, under constant stirring, 1 part of the strongest water of ammonia. Soak the goods in this solution for 2 hours, then let them be washed as usual for fine flannels. A better process, in the hands of experts, is to soak the goods for an hour or so in a dilute solution of sodium hyposulphite, remove, add to the solution sufficient dilute hydrochloric acid to decompose the hyposulphite. Replace the goods, cover the tub closely, and let remain for 15 minutes longer. Then remove the running water, if convenient, and if not, wring out quickly, and rinse in clear water. One not an expert at such work must be very careful in the rinsing, as care must be taken to get out every trace of chemical. This is best done by a second rinsing.
The following is said to make a fine, jet-black laundry ink:
a. Copper chloride crystals............. 85 parts
Sodium chlorate. . . . 106 parts
Ammonium chloride 53 parts
Water, distilled..... 600 parts
b. Glycerine.......... 100 parts
Mucilage gum arabic (gum, 1 part; water, 2 parts).. .. 200 parts
Aniline hydrochlorate.............. 200 parts
Distilled water...... 300 parts