Scotch law. The incapacity to exercise the power of disposing of one’s property after being attacked with a mortal disease. 2. It commences with the beginning of such disease. 3. There are two exceptions to this general rule, namely: 1. If he survive for sixty days after the act or, 2. If he go to kirk or market unattended. He is then said to be in legitima potestate, or in liege poustie. 1 Bell’s Com. 84, 85.