 Zhang Yi wrote the "Guangya" as a supplement to the centuries older "Erya" dictionary.He used the same 19 chapter divisions into lexical categories, and numerous "Guangya" entries are abstract words under the first three chapters "Shigu" (釋詁 "Explaining Old Words"), "Shiyan" (釋言 "Explaining Words"), and "Shixun" (釋訓 "Explaining Instructions").Based upon entries in the "Guangya" biological chapters, Joseph Needham et al.