Concrete in the country / [American Cement Company]. (1910)
American Cement Company · Association of American Portland Cement Manufacturers · leaf 53
I I r i ill •HililiHl … I I * 1 3 ^1 Concrete Barn Floors Investigations of the Department of Agriculture have disclosed the fact thatmany cases of typhoid fever and malaria, often considered unaccountable in theirongm, are the result of the germs being carried by the house-flv. Screens fiy-paper, and_ poisons are all…