<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31410816</termId><termName>natron</termName><termType>PT</termType><termNote><![CDATA[ Hydrous sodium carbonate found in nature as evaporative residues. Used widely as a silica source in early glass manufacture; in ancient Egypt used as well as a bleach for linen, a preservative in mummification, and as an ingredient of incense.  ]]></termNote><termCreatedDate>2026-03-30 20:50:27</termCreatedDate><relation><relationType>BT</relationType><termId>31373639</termId><termName>sodium carbonate</termName><termType>PT</termType></relation></term>  </Zthes>