<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31320519</termId><termName>ammonium carbonate</termName><termType>PT</termType><termNote><![CDATA[ Refers to a carbonate of ammonium commonly known as hartshorn. It is a white powder used in smelling salts, baking powder, textile dyeing, and other applications. In conservation, a solution of ammonium carbonate is used as a solubilizing agent for extraction of soluble salts present on deteriorated stone surfaces. ]]></termNote><termCreatedDate>2026-03-30 20:26:23</termCreatedDate><relation><relationType>UF</relationType><termId>31320520</termId><termName>carbonate, ammonium</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31320521</termId><termName>hartshorn</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31306143</termId><termName>inorganic material</termName><termType>PT</termType></relation></term>  </Zthes>