An action may be dismissed, without prejudice to a future action:

First, By the plaintiff, before the final submission of the case to the jury, or to the court, where the trial is by the court.

Second, By the court, where the plaintiff fails to appear on the trial.

Third, By the court, for the want of necessary parties.

Fourth, By the court, on the application of some of the defendants, where there are others whom the plaintiff fails to prosecute with diligence.

Fifth, By the court, for disobedience by the plaintiff of an order concerning the proceedings in the action.

Sixth, In all other cases, upon the trial of the action, the decision must be upon the merits.

R.L. 1910, § 5125.