Section 70. Upon motion of a party, or whenever the court deems it appropriate, the court shall include in its charge to the jury an instruction which in substance states that no duly impanelled trial juror is better qualified to determine the truth of the facts in controversy or to deliberate upon a verdict solely because of his occupation or reputation. The court shall have discretion to express this instruction in whatever language it deems appropriate and to supplement, elaborate, or explain this instruction to the jury with reference to the particular case being submitted to it. This section shall not be construed as a limitation in any way upon the authority of the court to make such further charges as are appropriate.