(a) A instigates a child to put poison into the food of Z, and gives him poison for that purpose. The child, in consequence of the instigation, by mistake puts the poison into the food of Y, which is by the side of that of Z. Here if the child was acting under the influence of A' s instigation, and the act done was under the circumstances a probable consequence of the abetment, A is liable in the same manner and to the same extent as if he had instigated the child to put the poison into the food of Y.