Sentence:  Glycerol, partially esterified with abietic acid is preferred although glycerol, etc., esterified with rosin, Congo, manila, the <WSD>pontianacs</WSD>, the shellacs, kauri, copal or other fossil resins may be used. 
Meaning of the word marked with <WSD> tags:  A fossil resin historically used in the production of some rubber, produced from the latex of (ver=190128).