By section 502 of the Code of Civil Procedure it is provided that, when an assignee of a claim sues upon it, a demand existing at the time of the assignment may be allowed as a counter-claim to the amount of the plaintiff’s demand. The case shows that the plaintiff is the assignee of a claim for rent. The defendant sets up a counter-claim for a breach of the contract under which the premises were leased. The court charged that the assignee stood in the place of his assignor for all damages sustained by the tenant on account of a breach of the landlord’s (assignor’s) agreement. This was erroneous. When the jury allowed a counter-claim to the extent of the plaintiff’s demand, the court should have told the jury to find for the defendant. The fact that the plaintiff’s attorney was the assignor of the claim has no relevancy in this respect. In the case of Patton v. Baking Powder Co., 114 N. Y. 1, 20 N. E. Rep. 621, the claim of the plaintiff, although sued as assignee, “ was his personally, and not as assignee. ” He assumed to perform the contract assigned to him which made him liable for damages for a breach of the contract. The judgment of the county court should be reversed, and a new trial granted, with costs to abide event.