“They say that the request was verbally agreed to. Now, I hold it to be perfectly incompetent to prove such a relaxation or departure from an important part of a written lease by parole evidence. It is in vain to say, we will prove such a request was made, and that the subsequent operations tend to shew, that they were acting upon an agreement. That is reasoning in a circle. The first thing to be established is, that there was such an agreement as that averred. Therefore, any operation which takes place after that date never can be of the smallest value in proving the existence of that agreement.”