The contract provides for the delivery of certain instruments. If a sale, there is a deed and often a bond and purchase money mortgage. These should be carefully examined to see that they are in accord with the contract; the deed that it conveys the proper estate, sufficiently describes the property and is in the form provided in the contract; the bond and mortgage that they are for the agreed amount and upon the terms set forth in the contract. They should then be signed and acknowledged and finally scrutinized to see that the execution is proper. It is usual also to have the seller execute what is known as an "affidavit of title," by which he swears to the fact that he owns the property, states how long he has owned it, that no one has made any claim to it, that his title has never been questioned, that there are no liens upon it except such as are specifically mentioned and that there are no judgments against him.