( ( ( Counter ( A device ) ) ( for ( ( counting ( nuclear disintegrations ) ) ( to ( measure radioactivity ) ) ) ) ) . )
(ROOT (S (VP (VB Counter) (NP (DT A) (NN device)) (PP (IN for) (S (VP (VBG counting) (NP (JJ nuclear) (NNS disintegrations)) (PP (TO to) (NP (NN measure) (NN radioactivity))))))) (. .)))
Counter A device for counting nuclear disintegrations to measure radioactivity.
(ROOT (S (NP (NP (DT The) (`` `) (NN counting) ('' ') (NN instrument)) (NP (NN geiger) (NN counter))) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN radioactivity))))))) (. .)))