Section 6. In matters connected with the assessment and collection of any sum leviable under this Act, an appea

16. In matters connected with the assessment and collection of any sum leviable under this Act, an appeal shall lie to the Commissioner from the order of the Collector, provided that such appeal be presented within thirty days from the date of the order. The Commissioner's decision on such appeal shall be final; but all such decisions may be reviewed by the Board of Revenue.