Math Roth: "My thought is that Nabokov is being precise here in making Kinbote imprecise. According to Webster's 2nd, a chemical reagent is "any substance which, because it takes part in certain reactions, is used in detecting, examining, or measuring other substances, in preparing material,
in developing photographs, etc."  Kinbote seems to be describing a catalyst..."

 

JM: On second thoughts, why the apparent mistake related to "chemical reagent" is not a Nabokovian slip (his experience in labs must have acquainted him with "catalysts" and "reagents"), instead of seeing it as Kinbote's? The word "catalyst" is used in a metaphorical sense in common-speech, whereas "chemical reagent" isn't. In this restricted sense, both words are not interchangeable even though, associatively, they may be remembered simultaneously. Had Kinbote's commentary indicated "a catalyst" his expression would not be incorrect.