In medical Jurisprudence. The incapacity for copulation or propagatingthe species. Properly used of the male; but it has also been used synonymously with”sterility.” Grif’feth v. Griff- eth, 102 111. 30S, 44 N. E. 820; Payne v. Payne. 40 Minn.407. 49 N. W. 230, 24 Am. St. Itep. 240; Kempf v. Kernpf, 34 Mo. 213.Impotentia excusat legem. Co. Litt. 29. The impossibility of doing what is requiredby the law excuses from the performance.