Sentence:  The <WSD>figging</WSD> is probably due to the separation of the potash salts of some of the fatty acids having a high solidifying point, i. e., [...] 
Meaning of the word marked with <WSD> tags:  (Development of) white streaks or granulations in soap, a natural development in some soaps once considered a sign of quality and therefore sometimes artificially imitated. (mid-1800s to mid-1900s)