The county clerk shall also keep a numerical index, in which shall be noted all deeds relating to tracts of land and units within unit ownership estates within the limits of such county, such index shall be divided into columns with the heads to each division of the pages designating the respective columns as follows, to-wit:

It shall be the duty of the county clerk to make correct entries in such numerical index of all instruments recorded concerning tracts of land under the appropriate heading, and in the subdivision devoted to the particular quarter section described in the instrument making the conveyance, and the county clerk shall enter in their appropriate division, before any other entries are made, all the transfers embraced in the instrument recorded within his office, commencing with the first.