It bears on it in this way, is it not a fact that Mrs. Vandemeyer committed a young relative of hers to your charge? Julius leaned forward eagerly.
The young relative is a niece. 
mnli hypothesis: The young relative is a niece.  premise: It bears on it in this way, is it not a fact that Mrs. Vandemeyer committed a young relative of hers to your charge? Julius leaned forward eagerly.