Section 85
SEC. 85. No court shall entertain any suit assailing the validity of a tax sale of land under this Act until the taxpayer shall have paid into court the amount for which the land was sold, together with interest at the rate of fifteen per centum per annum upon that sum from the date of sale to the time of instituting suit. The money so paid into court shall belong to the purchaser at the tax sale if the deed is declared invalid, and shall be returned to the depositor should he fail in his action.