Summary of Mitchill vs. Lath
Ct. of App. NY 
Relevant Facts: The df/pet Laths owned a farm that they wished to sell, but there was an ice house they owned across the road. Pl/res Mitchill wanted to purchase the land but found the ice house objectionable. Mitchill claims “Df orally promised and agreed, for and in consideration of the purchase of their farm." Pl then made a written contract to buy the property for $8400, cash and mortgage. She received the deed, entered into possession, and made improvements. The df have not had the ice house removed and do not intend to do so.
Legal Issue(s): Whether the oral agreement, to remove the ice house, apart from the written contract may be enforced?
Court’s Holding: No
Procedure: Judgment of the Appellate Division and Special Term of S. Ct for PL, reversed and the complaint dismissed.
Law or Rule(s): Standard to Measure closeness of the bond between: An oral agreement modifying a written contract must have 1) the agreement must in form be a collateral one; 2) it must not contradict express or implied provisions of the written contract; 3) it must be one that the parties would have ordinarily be expected to embody in the writing (the oral agreement must not be so clearly connected w/ the principal transaction as to be part and parcel of it).
Court Rationale: There is a written contract for the purchase and sale of land, $8400. The property is described by survey, and a full covenant deed of the premises was granted. An inspection of this contract shows a full and complete agreement, setting forth in detail the obligations of each party. The removal of the ice house is collateral in form, but it is closely related to the subject dealt with in the written agreement -so closely that it may not be proven. The Pl was personally part of the process from start to finish. The deed was handed to her, she signed the written contract.
Plaintiff’s Argument: The agreement to remove the ice house was based on the same consideration to be performed by the dfs after the conveyance was complete.
Defendant’s Argument: Removal of the ice house was not a condition within the written contract for the sale of the property.
DISSENT: The written contract and the oral contract are bound together, using the same consideration. The problem is determining whether that bond is sufficiently close enough.
collateral – secondary or to act as a security or bond. An implied provision concerning further obligations can exist only if it “so clearly connected with the principal transaction as to be part and parcel of it."
Exclusion of proof of the oral agreement on the ground that it modifies the written contract may be based only upon a finding that the written contract was intended to cover the oral negotiation for the removal of the ice house which lead to the contract of purchase and sale. To determine what the writing was intended to cover the subject matter of the writing with the subject matter of the negotiation.