1917
Can. 1098 A person contracts invalidly who enters into a marriage deceived by malice, perpetrated to obtain consent, concerning some quality of the other partner which by its very nature can gravely disturb the partnership of conjugal life.
Ok, this is a good start. But you can't read 1 canon in isolation. Keep reading.
Or...you can read pre-V2 commentary on canon law, like Yeti posted, and take their advice.