(d) A without any excuse fires a loaded cannon into a crowd of persons and kills one of them. A is guilty of murder, although he may not have had a premeditated design to kill any particular individual. Exception 1.- When culpable homicide is not murder.- Culpable homicide is not murder if the offender, whilst deprived of the power of self- control by grave and sudden provocation, causes the death of the person who gave the provocation or causes the death of any other person by mistake or accident. The above exception is subject to the following provisos:- First.- That the provocation is not sought or voluntarily provoked by the offender as an excuse for killing or doing harm to any person. Secondly.- That the provocation is not given by anything done in obedience to the law, or by a public servant in the lawful exercise of the powers of such public servant. Thirdly.- That the provocation is not given by anything done in the lawful exercise of the right of private defence. Explanation.- Whether the provocation was grave and sudden enough to prevent the offence from amounting to murder is a question of fact. Illustrations