Wisconsin constitution
Article X: education
Section 8

Provision shall be made by law for the sale of all school and university lands after they shall have been appraised; and when any portion of such lands shall be sold and the purchase money shall not be paid at the time of the sale, the commissioners shall take security by mortgage upon the lands sold for the sum remaining unpaid, with seven per cent interest thereon, payable annually at the office of the treasurer. The commissioners shall be authorized to execute a good and sufficient conveyance to all purchasers of such lands, and to discharge any mortgages taken as security, when the sum due thereon shall have been paid. The commissioners shall have power to withhold from sale any portion of such lands when they shall deem it expedient, and shall invest all moneys arising from the sale of such lands, as well as all other university and school funds, in such manner as the legislature shall provide, and shall give such security for the faithful performance of their duties as may be required by law.