21 - Presumptions.

§  21.  Presumptions. In any proceeding for the enforcement of a claim  for compensation under this chapter, it shall be presumed in the absence  of substantial evidence to the contrary    1. That the claim comes within the provision of this chapter;    2. That sufficient notice thereof was given;    3. That the injury was not occasioned by the willful intention of  the  injured  employee  to  bring  about the injury or death of himself or of  another;    4. That the injury did not result solely from the intoxication of  the  injured employee while on duty.    5.  That  the  contents  of medical and surgical reports introduced in  evidence by claimants for  compensation  shall  constitute  prima  facie  evidence of fact as to the matter contained therein.