Sentence:  During the decade that followed , the common man , as that piece put it , grew uncomfortable as the Voice of God and fled from behind Saint Woodrow ( Wilson ) only to learn from Science , to his shocked relief that after all there was no God he had to speak for and that he was just an animal anyhow - that there was a <WSD>chemical</WSD> formula for him , and that too much could n't be expected of him . 
Meaning of the word marked with <WSD> tags:  a representation of a substance using symbols for its constituent elements