The Michigan school for the deaf, located in the city of Flint in the county of Genesee, and the Michigan school for the blind, located in the city of Lansing in the county of Ingham, are hereby declared to be public schools of the state of Michigan. They shall have for their object the education of such of the children in the state as may not by reason of the impairment of their sense of hearing or their sense of sight be advantageously educated in other public schools of the state. Said schools shall not be regarded or classed as charitable institutions.