Why is the lieutenant pleased with Henry's behavior?

He was pleased with Henry because he fought like a barbarian and helped the regiment drive back the enemy.

“Hot work! Hot work!” cried the lieu-tenant deliriously. He walked up and down, restless and eager. Sometimes his voice could be heard in a wild, incomprehensible laugh.

When he had a particularly profound thought upon the science of war he always unconsciously addressed himself to the youth."