Sentence:  Thus I. and L. Camus report some apparent variations, and recently Hoke and Rihl state that “ <WSD>hyperideal</WSD> ” is twenty times more toxic than salvarsan, and that these differences in toxicity are especially pronounced in the acid solutions. 
Meaning of the word marked with <WSD> tags:  A form of salvarsan that was introduced by (Paul Ehrlich), but soon found to be prone to severe side effects.