Responsa על בבא בתרא 151:3

Q - A woman presented her husband a dowry of interest bearing notes (the notes were drawn up by a non-Jewish notary). The husband died, and his heirs claim that these notes became his property, and even though the woman is entitled to receive them back as part of her Ketubah, nevertheless the interest accrued in his lifetime belongs entirely to them. The woman disputes their claim.
A - The notes and accrued interest belong to the woman, since the mere handing over of notes to the husband did not transfer to him the indebtedness contained therein; for she did not recite the formula, "acquire this and all obligations therein".