Cantonal tax law; arbitrariness in the taxation of commercial companies; depreciation of balance-sheet securities. For commercial companies, the balance sheet encompasses the whole corporate activity and not merely assets directly tied to operations; depreciation is not confined in principle to operating assets but may extend to all balance-sheet items. It is arbitrary to rely on non-operating assets when this increases taxable income while refusing to consider them when depreciation would benefit the taxpayer. Where the factual justification of the depreciation remains open, the matter must be remitted for new assessment (consid. 1).