The first mortgage bonds of this company cover all of its property acquired and to be acquired except land grant from the State of Minnesota. The income certificates may be issued to an amount not exceeding the first mortgage bonds issued and outstanding; $3,500,000 are now issued and sold. They do not constitute an indebtedness of the railroad company, or a claim against it, except that a sum not exceeding six per cent on their face per annum may be declared available by the board of directors for the payment of dividends on same out of the net income of the company in any one year, provided that no dividends shall be paid in any year upon the capital stock of the company until fully six per centum has been paid in that year upon all outstanding income certificates.