"The reading of the card persuaded me that he was dead"

Alice here: It's interesting how the boy learns from words.  We have the three words at the start that he has been brooding over, simony, paralysis, gnomon.  Now it's almost that he must read the announcement of the death to believe  it, even though his uncle has told him verbally.  So it's not the spoken word, but the visualized word that holds convincing meaning for the boy.