A writ formerly granted for freeing and discharging persons from serving on assizes and juries. Fitzh. Nat. Brev. 165. Non possessorl incumbit neeessitas probandi possessiones ad se pertinere. A person in possession is not bound to prove that the possessions belong to him. Broom, Max. 714. Non potest adduci exceptio ejus rei cujus petitur dissolutio. An exception of the same thing whose avoidance is sought cannot be made. Broom, Max. 100. Non potest probari quod probatum non relevat. 1 Exch. 91, 92. That cannot be proved which, if proved, is immaterial. Non potest qnis sine brevi agere. No one can sue without a writ. Fleta, lib. 2, c. 13,