<?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">hydrogen sulfide</topic></authority><related type="broader"><topic>sulfide</topic></related><variant type="other"><topic>hydrogen sulphide</topic></variant><variant type="other"><topic>sewer gas</topic></variant><variant type="other"><topic>sulfereted hydrogen</topic></variant><variant type="other"><topic>sulfide, hydrogen</topic></variant><variant type="other"><topic>sulfur hydride</topic></variant><variant type="other"><topic>sulphide, hydrogen</topic></variant><variant type="other"><topic>sulphuretted hydrogen</topic></variant> <note xml:lang="en"><![CDATA[ Toxic, flammable, colorless gas that smells like rotten eggs. Hydrogen sulfide may be created by decay of organic matter or obtained as a byproduct of refining carbonaceous fuels such as natural gas, crude oil, and coal. As an atmospheric pollutant, hydrogen sulfide blackens lead pigments, and tarnishes silver. ]]></note></mads>