Newfoundland and Labrador Corporation Ltd. et al. v. Attorney General of Newfoundland, 138 DLR (3d) 577, [1982] 2 SCR 260 -- summary under Non-Business-Income Tax

In finding that a tax of 15% imposed on gross income of a taxpayer from mine operations minus deductions for reasonable expenses and outlays, depreciation, pre-production development expenditures, and doubtful debt reserves constituted an income tax, Martland J. found (p. 586) that the fact that the tax was upon a particular component of the taxpayer's income did not alter its character as an income tax. In finding that a tax imposed on royalties received by persons for the granting of the right to mine properties minus deductions for administrative, accounting, legal and similar expenses; outlays incurred by the taxpayer within the area of the land; and rents and royalties; constituted an income tax, Martland J. noted (p. 588) that it was reasonable, in the case of a person not actually mining the land, for the list of permissible deductions to be more limited.