<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">ammonium carbonate</topic></authority><related type="broader"><topic>inorganic material</topic></related><variant type="other"><topic>carbonate, ammonium</topic></variant><variant type="other"><topic>hartshorn</topic></variant> <note xml:lang="en"><![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. ]]></note></mads>