¶1This action is unlawful detainer. The-affidavit to the complaint is made by plaintiffs agent, who “ on his oath says that the foregoing complaint is true in substance”’ Objection is made that the affidavit-is insufficient by reason of being qualified by the words- “ in substance.” We think the objection is well taken. There is no necessity for experiments in matters of this *433nature, especially when they are jurisdictional. The affiant swears that the matters, which he conceives to be of substance in the complaint, are true.
¶2Those matters which he may think are not of substance are not sworn to. This would leave the matter a question of opinion.
¶3As the affidavit is jurisdictional, we will reverse the judgment and dismiss the case. Fletcher v. Keyte, 66 Mo. 285.