The bolded words reveal Muir's attitude because it is meant to emphasize the meeting he had with the Calypso and what he learned. The bold indicates that he learned truly how powerful a plant had on the human hearts. When he used the bold, it indicated a positive and serious attitude combined for those reasons.
While the view of the first paragraph was dark and hopeless, the second depicted revival and hope. The impact of these two paragraphs being placed together manipulates the readers emotions, through the use of pathos, to increasingly believe the true power of Calypso. Without this prevelant juxtaposition the writings made by Muir would have been far less convinving.
