( ( Following Empedocles ) ( , ( ( ( all substances ) ( within ( the ( sublunary sphere ) ) ) ) ( ( were ( assumed ( to ( vary ( in ( ( their ( constituent ( classical elements ) ) ) ( of ( earth ( , ( water ( , ( ( air and ) fire ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (VBG Following) (NP (NNP Empedocles))) (, ,) (NP (NP (DT all) (NNS substances)) (PP (IN within) (NP (DT the) (JJ sublunary) (NN sphere)))) (VP (VBD were) (VP (VBN assumed) (S (VP (TO to) (VP (VB vary) (PP (IN in) (NP (NP (PRP$ their) (JJ constituent) (JJ classical) (NNS elements)) (PP (IN of) (NP (NN earth) (, ,) (NN water) (, ,) (NN air) (CC and) (NN fire)))))))))) (. .)))
Following Empedocles, all substances within the sublunary sphere were assumed to vary in their constituent classical elements of earth, water, air and fire.
(ROOT (S (NP (NNP Air)) (VP (MD can) (VP (VB be) (VP (VBN separated) (PP (IN into) (NP (JJ several) (NNS elements)))))) (. .)))