Ohio Revised Code Title XXXIX. Insurance § 3925.09

No insurance company shall own more than one fourth of the capital stock of a national bank, nor invest in or loan on the stocks and bonds, both included, of any railroad company, to an extent exceeding one fifth of its own capital and surplus, nor in the aggregate shall the investment in and loan on all railroad property exceed one fourth of its own capital and surplus.  Not more than one half of its capital and surplus shall be loaned on mortgages of real estate, as provided in sections 3925.05 of the Revised Code for the investment thereof, and not more than one tenth of the capital and surplus actually existing of such a company shall be invested in a single mortgage.  The current market value of the evidences of indebtedness mentioned in this section, in which the accumulations or surplus money above the capital stock of an insurance company may be loaned or invested, must be at all times during the continuance of the loans at least twenty per cent more than the sum loaned thereon.