In the first chapter of The Red Badge of Courage, what words does the author use to show a sarcastic tone?

In The Red Badge of Courage, Stephen Crane reveals a world long lost.  A world filled with bloody violence and chaos.  A world that was the Civil War Era.  In the first chapter, Crane remains serious, but not without some comedic relief.  One veteran said of Henry, "yer a right dum good feller."  Also, when Henry is expecting a romantic answer from his mother about war, she bluntly tells him to send back his socks when they get holes in them and not to drink and swear and to be a good boy.  This is comedic relief, but not necessarily sarcasm. 

Sarcasm is defined by comments that are opposite of the blatantly obvious, or sharp comments that most people know to be untrue.  There is really none of this in the first chapter.  The ideas expressed in the first chapter are mostly romantic, how Henry thinks he will save people in war with his "eagle-eyed prowess."  And of indecision, as Henry is not sure if he will fight or run.  But sarcasm is not really implemented by Crane in the first chapter.