Evidence was introduced of experiments made by the sheriff and another party in regard to the effect of powder fired from a pistol upon a pasteboard at distances ranging from 10 down to 3 feet. This seems to have been admitted in order to show the distance of the weapon from deceased's head at the time of the homicide. . . .The evidence of experiments testified to by the sheriff should have been excluded. Test on the pasteboard was not similar, or nearly so. to firing at skin of the human being.