Presumptions.

In any proceeding for the enforcement of a claim for compensation under this chapter it shall be presumed, in the absence of evidence to the contrary: That the claim comes within the provisions of this chapter; That sufficient notice of such claim has been given; That the injury was not occasioned solely by the intoxication of the injured employee; and That the injury was not occasioned by the willful intention of the injured employee to injure or kill himself or another.