In charging the jury, the court must state to them all matters of law which it thinks necessary for their information in giving their verdict, and if it state the testimony of the case, it must in addition inform the jury that they are the exclusive judges of all questions of fact. Either party may present to the court any written charge and request that it be given. If the court thinks it correct and pertinent, it must be given; if not, it must be refused. Upon each charge presented and given or refused the court must endorse or sign its decision. If part of any written charge be given and part refused the court must distinguish, showing by the endorsement or answer what part of each charge was given and what part refused.
R.L. 1910, § 5905.