Sentence:  And there was the case of Tom Hepker , a machinist , who was referred by a friend to a health machine quack who treated him with a so-called diagnostic machine for what Doctor Fraud said was a system full of <WSD>arsenic</WSD> and strychnine . 
Meaning of the word marked with <WSD> tags:  a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer