The court may permit the jury to separate at any adjournment or recess of the court during the trial and jury deliberation in all cases of misdemeanor or felony, except in capital cases. When the jurors are permitted to separate, after being impaneled as provided for in sections 494.400 to 494.505, and at each adjournment the court shall admonish them that it is their duty not to converse among themselves, nor to suffer others to converse with them or in their hearing on any subject connected with the trial, or to form or express any opinion thereon, until the cause is finally submitted to them, or until they return to the jury room to continue their deliberations.