Sentence:  The light was filtered by the soft glass window of the thermostat thus ensuring that only light absorbed by the chlorine and not by the <WSD>carbon</WSD> tetrachloride could enter the reaction cell . 
Meaning of the word marked with <WSD> tags:  a colorless nonflammable liquid used as a solvent for fats and oils; because of its toxicity its use as a cleaning fluid or fire extinguisher has declined