Whoever shall stab or thrust any person who has not then any weapon drawn or who has not then first stricken the person who shall so stab or thrust, so that the person so stabbed or thrust shall thereof die within the space of six months then next following, although it cannot be proved that the same was done of malice aforethought, yet the party so offending, and being thereof convicted, shall suffer death as in the case of wilful murder; provided , that nothing herein contained shall extend to any person:

1. (1) Who shall kill any person in self-defense or by misfortune or in any other manner than as aforesaid;
2. (2) Who, in keeping and preserving the peace, shall chance to commit manslaughter if such manslaughter be not committed wittingly, willingly and of purpose under pretext and color of keeping the peace; nor
3. (3) Who, in chastising or correcting his child, shall, besides his intent and purpose, chance to commit manslaughter.