why did mr.otis refused to accept the box of jewels?

Mr. Otis is the quintessential honest minister and Puritan by belief. He thought that the jewels were unnecessary for a young girl like Virginia Otis. Moreover, he also believed that the jewels were Canterville family heirlooms and hence, he wished to return them to Lord Canterville. He wanted to prevent Virginia from becoming vain and also wanted to return the jewels to Lord Canterville, whom Mr. Otis considered to be the rightful owner.