The property accounts set up, maintained and kept as provided by law, for tangible property and equipment, other than expendable supplies, shall be maintained on cost basis, representative of capital values of invested state monies, and never charged with appreciation nor credited with depreciation; but on sale or exchange and reacquisition of properties of comparable function as hereinbefore provided, the capital account thereof shall be credited with the first or capital cost of the item disposed of and charged with the gross cost of the substitute item acquired; unless and until the Legislature shall require that the depleted or depreciated value shall be charged to expense.
Laws 1949, p. 419, § 4.