( ( The reaction ) ( ( ( ( ( gave off ) ( hydrogen ( sulfide gas ) ) ) , ) ( while ( ( the ( sulfur auretum ) ) ( precipitated ( to ( ( the bottom ) ( of ( the container ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN reaction)) (VP (VBD gave) (PRT (RP off)) (NP (NN hydrogen) (NN sulfide) (NN gas)) (, ,) (SBAR (IN while) (S (NP (DT the) (NN sulfur) (NN auretum)) (VP (VBD precipitated) (PP (TO to) (NP (NP (DT the) (NN bottom)) (PP (IN of) (NP (DT the) (NN container))))))))) (. .)))
The reaction gave off hydrogen sulfide gas, while the sulfur auretum precipitated to the bottom of the container.
(ROOT (S (NP (NNP Hydrogen) (NNP sulfide)) (VP (VBZ is) (NP (NP (DT a) (ADJP (JJ noxious) (CC and) (JJ toxic)) (NN gas)) (VP (VBN produced) (PP (IN from) (S (VP (VBG decaying) (NP (JJ organic) (NN matter)))))) (SBAR (WHNP (WDT that)) (S (VP (VBZ contains) (NP (NN sulfur))))))) (. .)))