When a lawful deed is raised, whereby it becomes void, the obligor may plead non, est factum, and give the matter in evidence, because at the time of the plea pleaded, it is not his deed." "Secondly, it was resolved, that when any deed is altered in a point material, by the plaintiff himself, or by any stranger, without the privity (1) , (2) 11 Co.Rep.26 b;77E.R.177. 80 of the obligee, be it by interlineation, addition, raising, or by drawing of a pen through a line, or through the midst of any material word, that the deed thereby becomes void . so if the obligee himself alters the deed by any of the said ways, although it is in words not material, yet the deed ,is void: but if a stranger, without his privity, alters the deed by any of the said ways in any point material, it shall not avoid the deed.