§ 4.   Banks and bankers taxed. The Legislature shall provide for taxing all moneys, credits, investments in bonds, stocks, joint stock companies, or otherwise; and also for taxing the notes and bills discounted or purchased, moneys loaned and all other property, effects or dues of every description, of all banks and of all bankers, so that all property employed in banking shall always be subject to a taxation equal to that imposed on the property of individuals.