Sodium Monochloroacetate Solution: Chloroacetic Acid Neutralised with Sodium Bicarbonate (Haskins and Maxwell, du Pont, US 2,131,733)

Chloroacetic acid is used as its sodium salt, which reacts cleanly with amines and cellulose. Haskins and Maxwell simply dissolved the acid in water and stirred in baking soda until it stopped fizzing. Result: about 223 parts sodium monochloroacetate in 375 parts water. Source: Haskins and Maxwell, US 2,131,733 (du Pont, 1938), Example 1. Picture drawn by Youblob.