Occupational disease: specified schedule diseases are presumed employment injuries unless rebutted; other diseases need specific accidental causation. Section 36 establishes a rebuttable statutory presumption that diseases listed in the Third Schedule, when contracted by employees in specified employments (with required continuous service periods for Parts B and C), are employment injuries arising out of and in the course of employment; otherwise, benefits require direct attribution to a specific accidental injury, and the general presumption in section 34(1) does not apply to these cases.