When there are several counts in a declaration, one or more of which are faulty, the defendant may demur to the faulty count or counts, or move the court to instruct the jury to disregard them. If he does neither, and entire damages be found, judgment shall be entered against the defendant for the damages found, if any count be good, although others be faulty, unless the court can plainly see that the verdict could not have been found on the good count. If he demurs to the faulty count, or moves the court to instruct the jury to disregard it, and his demurrer or motion is overruled, and entire damages be found, and it cannot be seen on which count the verdict was founded, if the jury has been discharged the verdict shall be set aside, but if it is manifest that the verdict could not have been found on the bad count, the verdict shall be allowed to stand. If the jury has not been discharged, the court shall send it back with instructions to designate on which count of the declaration its verdict is found.