18. " Misrepresentation" defined.-" Misrepresentation" means and includes-
the positive assertion, in a manner not warranted by the information of the person making it, of that which is not true, though he believes it to be true
any breach, of duty which, without an intent to deceive, gains an advantage to the person committing it, or any one claiming under him, by misleading another to his prejudice or to the prejudice of any one claiming under him;
causing, however innocently, a party to an agreement to make a mistake as to the substance of the thing which is the subject of the agreement.